reactor.core.publisher

Class Flux<T>

java.lang.Object

reactor.core.publisher.Flux<T>

Type Parameters:

T - the element type of this Reactive Streams Publisher

All Implemented Interfaces:

Publisher<T>

Direct Known Subclasses:

ConnectableFlux, FluxOperator, FluxProcessor, GroupedFlux

public abstract class Flux<T>
extends Object
implements Publisher<T>

A Reactive Streams Publisher with rx operators that emits 0 to N elements, and then completes (successfully or with an error).

It is intended to be used in implementations and return types. Input parameters should keep using raw Publisher as much as possible.

If it is known that the underlying Publisher will emit 0 or 1 element, Mono should be used instead.

Note that using state in the java.util.function / lambdas used within Flux operators should be avoided, as these may be shared between several Subscribers.

subscribe(CoreSubscriber) is an internal extension to subscribe(Subscriber) used internally for Context passing. User provided Subscriber may be passed to this "subscribe" extension but will loose the available per-subscribe @link Hooks#onLastOperator}.

Author:

Sebastien Deleuze, Stephane Maldini, David Karnok, Simon Baslé

See Also:

Mono

Constructor Summary

Constructors

Constructor and Description
Flux()

Method Summary

Modifier and Type	Method and Description
Mono<Boolean>	all(Predicate<? super T> predicate) Emit a single boolean true if all values of this sequence match the Predicate.
Mono<Boolean>	any(Predicate<? super T> predicate) Emit a single boolean true if any of the values of this Flux sequence match the predicate.
<P> P	as(Function<? super Flux<T>,P> transformer) Transform this Flux into a target type.
T	blockFirst() Subscribe to this Flux and block indefinitely until the upstream signals its first value or completes.
T	blockFirst(Duration timeout) Subscribe to this Flux and block until the upstream signals its first value, completes or a timeout expires.
T	blockLast() Subscribe to this Flux and block indefinitely until the upstream signals its last value or completes.
T	blockLast(Duration timeout) Subscribe to this Flux and block until the upstream signals its last value, completes or a timeout expires.
Flux<List<T>>	buffer() Collect all incoming values into a single List buffer that will be emitted by the returned Flux once this Flux completes.
Flux<List<T>>	buffer(Duration timespan) Collect incoming values into multiple List buffers that will be emitted by the returned Flux every timespan.
Flux<List<T>>	buffer(Duration timespan, Duration timeshift) Collect incoming values into multiple List buffers created at a given timeshift period.
Flux<List<T>>	buffer(Duration timespan, Duration timeshift, Scheduler timer) Collect incoming values into multiple List buffers created at a given timeshift period, as measured on the provided Scheduler.
Flux<List<T>>	buffer(Duration timespan, Scheduler timer) Collect incoming values into multiple List buffers that will be emitted by the returned Flux every timespan, as measured on the provided Scheduler.
Flux<List<T>>	buffer(int maxSize) Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.
Flux<List<T>>	buffer(int maxSize, int skip) Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.
<C extends Collection<? super T>> Flux<C>	buffer(int maxSize, int skip, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.
<C extends Collection<? super T>> Flux<C>	buffer(int maxSize, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.
Flux<List<T>>	buffer(Publisher<?> other) Collect incoming values into multiple List buffers, as delimited by the signals of a companion Publisher this operator will subscribe to.
<C extends Collection<? super T>> Flux<C>	buffer(Publisher<?> other, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers, as delimited by the signals of a companion Publisher this operator will subscribe to.
Flux<List<T>>	bufferTimeout(int maxSize, Duration timespan) Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses.
Flux<List<T>>	bufferTimeout(int maxSize, Duration timespan, Scheduler timer) Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses, as measured on the provided Scheduler.
<C extends Collection<? super T>> Flux<C>	bufferTimeout(int maxSize, Duration timespan, Scheduler timer, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses, as measured on the provided Scheduler.
<C extends Collection<? super T>> Flux<C>	bufferTimeout(int maxSize, Duration timespan, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses.
Flux<List<T>>	bufferUntil(Predicate<? super T> predicate) Collect incoming values into multiple List buffers that will be emitted by the resulting Flux each time the given predicate returns true.
Flux<List<T>>	bufferUntil(Predicate<? super T> predicate, boolean cutBefore) Collect incoming values into multiple List buffers that will be emitted by the resulting Flux each time the given predicate returns true.
<U,V> Flux<List<T>>	bufferWhen(Publisher<U> bucketOpening, Function<? super U,? extends Publisher<V>> closeSelector) Collect incoming values into multiple List buffers started each time an opening companion Publisher emits.
<U,V,C extends Collection<? super T>> Flux<C>	bufferWhen(Publisher<U> bucketOpening, Function<? super U,? extends Publisher<V>> closeSelector, Supplier<C> bufferSupplier) Collect incoming values into multiple user-defined Collection buffers started each time an opening companion Publisher emits.
Flux<List<T>>	bufferWhile(Predicate<? super T> predicate) Collect incoming values into multiple List buffers that will be emitted by the resulting Flux.
Flux<T>	cache() Turn this Flux into a hot source and cache last emitted signals for further Subscriber.
Flux<T>	cache(Duration ttl) Turn this Flux into a hot source and cache last emitted signals for further Subscriber.
Flux<T>	cache(int history) Turn this Flux into a hot source and cache last emitted signals for further Subscriber.
Flux<T>	cache(int history, Duration ttl) Turn this Flux into a hot source and cache last emitted signals for further Subscriber.
Flux<T>	cancelOn(Scheduler scheduler) Prepare this Flux so that subscribers will cancel from it on a specified Scheduler.
<E> Flux<E>	cast(Class<E> clazz) Cast the current Flux produced type into a target produced type.
Flux<T>	checkpoint() Activate assembly tracing for this particular Flux, in case of an error upstream of the checkpoint.
Flux<T>	checkpoint(String description) Activate assembly marker for this particular Flux by giving it a description that will be reflected in the assembly traceback in case of an error upstream of the checkpoint.
Flux<T>	checkpoint(String description, boolean forceStackTrace) Activate assembly tracing or the lighter assembly marking depending on the forceStackTrace option.
<R,A> Mono<R>	collect(Collector<? super T,A,? extends R> collector) Collect all elements emitted by this Flux into a container, by applying a Java 8 Stream API Collector The collected result will be emitted when this sequence completes.
<E> Mono<E>	collect(Supplier<E> containerSupplier, BiConsumer<E,? super T> collector) Collect all elements emitted by this Flux into a user-defined container, by applying a collector BiConsumer taking the container and each element.
Mono<List<T>>	collectList() Collect all elements emitted by this Flux into a List that is emitted by the resulting Mono when this sequence completes.
<K> Mono<Map<K,T>>	collectMap(Function<? super T,? extends K> keyExtractor) Collect all elements emitted by this Flux into a hashed Map that is emitted by the resulting Mono when this sequence completes.
<K,V> Mono<Map<K,V>>	collectMap(Function<? super T,? extends K> keyExtractor, Function<? super T,? extends V> valueExtractor) Collect all elements emitted by this Flux into a hashed Map that is emitted by the resulting Mono when this sequence completes.
<K,V> Mono<Map<K,V>>	collectMap(Function<? super T,? extends K> keyExtractor, Function<? super T,? extends V> valueExtractor, Supplier<Map<K,V>> mapSupplier) Collect all elements emitted by this Flux into a user-defined Map that is emitted by the resulting Mono when this sequence completes.
<K> Mono<Map<K,Collection<T>>>	collectMultimap(Function<? super T,? extends K> keyExtractor) Collect all elements emitted by this Flux into a multimap that is emitted by the resulting Mono when this sequence completes.
<K,V> Mono<Map<K,Collection<V>>>	collectMultimap(Function<? super T,? extends K> keyExtractor, Function<? super T,? extends V> valueExtractor) Collect all elements emitted by this Flux into a multimap that is emitted by the resulting Mono when this sequence completes.
<K,V> Mono<Map<K,Collection<V>>>	collectMultimap(Function<? super T,? extends K> keyExtractor, Function<? super T,? extends V> valueExtractor, Supplier<Map<K,Collection<V>>> mapSupplier) Collect all elements emitted by this Flux into a user-defined multimap that is emitted by the resulting Mono when this sequence completes.
Mono<List<T>>	collectSortedList() Collect all elements emitted by this Flux until this sequence completes, and then sort them in natural order into a List that is emitted by the resulting Mono.
Mono<List<T>>	collectSortedList(Comparator<? super T> comparator) Collect all elements emitted by this Flux until this sequence completes, and then sort them using a Comparator into a List that is emitted by the resulting Mono.
static <T,V> Flux<V>	combineLatest(Function<Object[],V> combinator, int prefetch, Publisher<? extends T>... sources) Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources.
static <T,V> Flux<V>	combineLatest(Function<Object[],V> combinator, Publisher<? extends T>... sources) Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources.
static <T,V> Flux<V>	combineLatest(Iterable<? extends Publisher<? extends T>> sources, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources provided in an Iterable.
static <T,V> Flux<V>	combineLatest(Iterable<? extends Publisher<? extends T>> sources, int prefetch, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources provided in an Iterable.
static <T1,T2,V> Flux<V>	combineLatest(Publisher<? extends T1> source1, Publisher<? extends T2> source2, BiFunction<? super T1,? super T2,? extends V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of two Publisher sources.
static <T1,T2,T3,V> Flux<V>	combineLatest(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of three Publisher sources.
static <T1,T2,T3,T4,V> Flux<V>	combineLatest(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of four Publisher sources.
static <T1,T2,T3,T4,T5,V> Flux<V>	combineLatest(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4, Publisher<? extends T5> source5, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of five Publisher sources.
static <T1,T2,T3,T4,T5,T6,V> Flux<V>	combineLatest(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4, Publisher<? extends T5> source5, Publisher<? extends T6> source6, Function<Object[],V> combinator) Build a Flux whose data are generated by the combination of the most recently published value from each of six Publisher sources.
<V> Flux<V>	compose(Function<? super Flux<T>,? extends Publisher<V>> transformer) Defer the transformation of this Flux in order to generate a target Flux type.
static <T> Flux<T>	concat(Iterable<? extends Publisher<? extends T>> sources) Concatenate all sources provided in an Iterable, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concat(Publisher<? extends Publisher<? extends T>> sources) Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concat(Publisher<? extends Publisher<? extends T>> sources, int prefetch) Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concat(Publisher<? extends T>... sources) Concatenate all sources provided as a vararg, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concatDelayError(Publisher<? extends Publisher<? extends T>> sources) Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concatDelayError(Publisher<? extends Publisher<? extends T>> sources, boolean delayUntilEnd, int prefetch) Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concatDelayError(Publisher<? extends Publisher<? extends T>> sources, int prefetch) Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.
static <T> Flux<T>	concatDelayError(Publisher<? extends T>... sources) Concatenate all sources provided as a vararg, forwarding elements emitted by the sources downstream.
<V> Flux<V>	concatMap(Function<? super T,? extends Publisher<? extends V>> mapper) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.
<V> Flux<V>	concatMap(Function<? super T,? extends Publisher<? extends V>> mapper, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.
<V> Flux<V>	concatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper, boolean delayUntilEnd, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.
<V> Flux<V>	concatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.
<V> Flux<V>	concatMapDelayError(Function<? super T,Publisher<? extends V>> mapper) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.
<R> Flux<R>	concatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper) Transform the items emitted by this Flux into Iterable, then flatten the elements from those by concatenating them into a single Flux.
<R> Flux<R>	concatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper, int prefetch) Transform the items emitted by this Flux into Iterable, then flatten the emissions from those by concatenating them into a single Flux.
Flux<T>	concatWith(Publisher<? extends T> other) Concatenate emissions of this Flux with the provided Publisher (no interleave).
Flux<T>	concatWithValues(T... values) Concatenates the values to the end of the Flux
Mono<Long>	count() Counts the number of values in this Flux.
static <T> Flux<T>	create(Consumer<? super FluxSink<T>> emitter) Programmatically create a Flux with the capability of emitting multiple elements in a synchronous or asynchronous manner through the FluxSink API.
static <T> Flux<T>	create(Consumer<? super FluxSink<T>> emitter, FluxSink.OverflowStrategy backpressure) Programmatically create a Flux with the capability of emitting multiple elements in a synchronous or asynchronous manner through the FluxSink API.
Flux<T>	defaultIfEmpty(T defaultV) Provide a default unique value if this sequence is completed without any data
static <T> Flux<T>	defer(Supplier<? extends Publisher<T>> supplier) Lazily supply a Publisher every time a Subscription is made on the resulting Flux, so the actual source instantiation is deferred until each subscribe and the Supplier can create a subscriber-specific instance.
Flux<T>	delayElements(Duration delay) Delay each of this Flux elements (Subscriber.onNext(T) signals) by a given Duration.
Flux<T>	delayElements(Duration delay, Scheduler timer) Delay each of this Flux elements (Subscriber.onNext(T) signals) by a given Duration.
Flux<T>	delaySequence(Duration delay) Shift this Flux forward in time by a given Duration.
Flux<T>	delaySequence(Duration delay, Scheduler timer) Shift this Flux forward in time by a given Duration.
Flux<T>	delaySubscription(Duration delay) Delay the subscription to this Flux source until the given period elapses.
Flux<T>	delaySubscription(Duration delay, Scheduler timer) Delay the subscription to this Flux source until the given period elapses, as measured on the user-provided Scheduler.
<U> Flux<T>	delaySubscription(Publisher<U> subscriptionDelay) Delay the subscription to this Flux source until another Publisher signals a value or completes.
Flux<T>	delayUntil(Function<? super T,? extends Publisher<?>> triggerProvider) Subscribe to this Flux and generate a Publisher from each of this Flux elements, each acting as a trigger for relaying said element.
<X> Flux<X>	dematerialize() An operator working only if this Flux emits onNext, onError or onComplete Signal instances, transforming these materialized signals into real signals on the Subscriber.
Flux<T>	distinct() For each Subscriber, track elements from this Flux that have been seen and filter out duplicates.
<V> Flux<T>	distinct(Function<? super T,? extends V> keySelector) For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by a key extracted through the user provided Function.
<V,C extends Collection<? super V>> Flux<T>	distinct(Function<? super T,? extends V> keySelector, Supplier<C> distinctCollectionSupplier) For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by a key extracted through the user provided Function and by the add method of the Collection supplied (typically a Set).
<V,C> Flux<T>	distinct(Function<? super T,? extends V> keySelector, Supplier<C> distinctStoreSupplier, BiPredicate<C,V> distinctPredicate, Consumer<C> cleanup) For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by applying a BiPredicate on an arbitrary user-supplied <C> store and a key extracted through the user provided Function.
Flux<T>	distinctUntilChanged() Filter out subsequent repetitions of an element (that is, if they arrive right after one another).
<V> Flux<T>	distinctUntilChanged(Function<? super T,? extends V> keySelector) Filter out subsequent repetitions of an element (that is, if they arrive right after one another), as compared by a key extracted through the user provided Function using equality.
<V> Flux<T>	distinctUntilChanged(Function<? super T,? extends V> keySelector, BiPredicate<? super V,? super V> keyComparator) Filter out subsequent repetitions of an element (that is, if they arrive right after one another), as compared by a key extracted through the user provided Function and then comparing keys with the supplied BiPredicate.
Flux<T>	doAfterTerminate(Runnable afterTerminate) Add behavior (side-effect) triggered after the Flux terminates, either by completing downstream successfully or with an error.
Flux<T>	doFinally(Consumer<SignalType> onFinally) Add behavior (side-effect) triggered after the Flux terminates for any reason, including cancellation.
Flux<T>	doOnCancel(Runnable onCancel) Add behavior (side-effect) triggered when the Flux is cancelled.
Flux<T>	doOnComplete(Runnable onComplete) Add behavior (side-effect) triggered when the Flux completes successfully.
Flux<T>	doOnEach(Consumer<? super Signal<T>> signalConsumer) Add behavior (side-effects) triggered when the Flux emits an item, fails with an error or completes successfully.
<E extends Throwable> Flux<T>	doOnError(Class<E> exceptionType, Consumer<? super E> onError) Add behavior (side-effect) triggered when the Flux completes with an error matching the given exception type.
Flux<T>	doOnError(Consumer<? super Throwable> onError) Add behavior (side-effect) triggered when the Flux completes with an error.
Flux<T>	doOnError(Predicate<? super Throwable> predicate, Consumer<? super Throwable> onError) Add behavior (side-effect) triggered when the Flux completes with an error matching the given exception.
Flux<T>	doOnNext(Consumer<? super T> onNext) Add behavior (side-effect) triggered when the Flux emits an item.
Flux<T>	doOnRequest(LongConsumer consumer) Add behavior (side-effect) triggering a LongConsumer when this Flux receives any request.
Flux<T>	doOnSubscribe(Consumer<? super Subscription> onSubscribe) Add behavior (side-effect) triggered when the Flux is subscribed.
Flux<T>	doOnTerminate(Runnable onTerminate) Add behavior (side-effect) triggered when the Flux terminates, either by completing successfully or with an error.
Flux<Tuple2<Long,T>>	elapsed() Map this Flux into Tuple2<Long, T> of timemillis and source data.
Flux<Tuple2<Long,T>>	elapsed(Scheduler scheduler) Map this Flux into Tuple2<Long, T> of timemillis and source data.
Mono<T>	elementAt(int index) Emit only the element at the given index position or IndexOutOfBoundsException if the sequence is shorter.
Mono<T>	elementAt(int index, T defaultValue) Emit only the element at the given index position or fall back to a default value if the sequence is shorter.
static <T> Flux<T>	empty() Create a Flux that completes without emitting any item.
static <T> Flux<T>	error(Throwable error) Create a Flux that terminates with the specified error immediately after being subscribed to.
static <O> Flux<O>	error(Throwable throwable, boolean whenRequested) Create a Flux that terminates with the specified error, either immediately after being subscribed to or after being first requested.
Flux<T>	expand(Function<? super T,? extends Publisher<? extends T>> expander) Recursively expand elements into a graph and emit all the resulting element using a breadth-first traversal strategy.
Flux<T>	expand(Function<? super T,? extends Publisher<? extends T>> expander, int capacityHint) Recursively expand elements into a graph and emit all the resulting element using a breadth-first traversal strategy.
Flux<T>	expandDeep(Function<? super T,? extends Publisher<? extends T>> expander) Recursively expand elements into a graph and emit all the resulting element, in a depth-first traversal order.
Flux<T>	expandDeep(Function<? super T,? extends Publisher<? extends T>> expander, int capacityHint) Recursively expand elements into a graph and emit all the resulting element, in a depth-first traversal order.
Flux<T>	filter(Predicate<? super T> p) Evaluate each source value against the given Predicate.
Flux<T>	filterWhen(Function<? super T,? extends Publisher<Boolean>> asyncPredicate) Test each value emitted by this Flux asynchronously using a generated Publisher<Boolean> test.
Flux<T>	filterWhen(Function<? super T,? extends Publisher<Boolean>> asyncPredicate, int bufferSize) Test each value emitted by this Flux asynchronously using a generated Publisher<Boolean> test.
static <I> Flux<I>	first(Iterable<? extends Publisher<? extends I>> sources) Pick the first Publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.
static <I> Flux<I>	first(Publisher<? extends I>... sources) Pick the first Publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.
<R> Flux<R>	flatMap(Function<? super T,? extends Publisher<? extends R>> mapper) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.
<R> Flux<R>	flatMap(Function<? super T,? extends Publisher<? extends R>> mapperOnNext, Function<? super Throwable,? extends Publisher<? extends R>> mapperOnError, Supplier<? extends Publisher<? extends R>> mapperOnComplete) Transform the signals emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.
<V> Flux<V>	flatMap(Function<? super T,? extends Publisher<? extends V>> mapper, int concurrency) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.
<V> Flux<V>	flatMap(Function<? super T,? extends Publisher<? extends V>> mapper, int concurrency, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.
<V> Flux<V>	flatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper, int concurrency, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.
<R> Flux<R>	flatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper) Transform the items emitted by this Flux into Iterable, then flatten the elements from those by merging them into a single Flux.
<R> Flux<R>	flatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper, int prefetch) Transform the items emitted by this Flux into Iterable, then flatten the emissions from those by merging them into a single Flux.
<R> Flux<R>	flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.
<R> Flux<R>	flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper, int maxConcurrency) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.
<R> Flux<R>	flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper, int maxConcurrency, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.
<R> Flux<R>	flatMapSequentialDelayError(Function<? super T,? extends Publisher<? extends R>> mapper, int maxConcurrency, int prefetch) Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.
static <T> Flux<T>	from(Publisher<? extends T> source) Decorate the specified Publisher with the Flux API.
static <T> Flux<T>	fromArray(T[] array) Create a Flux that emits the items contained in the provided array.
static <T> Flux<T>	fromIterable(Iterable<? extends T> it) Create a Flux that emits the items contained in the provided Iterable.
static <T> Flux<T>	fromStream(Stream<? extends T> s) Create a Flux that emits the items contained in the provided Stream.
static <T> Flux<T>	fromStream(Supplier<Stream<? extends T>> streamSupplier) Create a Flux that emits the items contained in a Stream created by the provided Supplier for each subscription.
static <T,S> Flux<T>	generate(Callable<S> stateSupplier, BiFunction<S,SynchronousSink<T>,S> generator) Programmatically create a Flux by generating signals one-by-one via a consumer callback and some state.
static <T,S> Flux<T>	generate(Callable<S> stateSupplier, BiFunction<S,SynchronousSink<T>,S> generator, Consumer<? super S> stateConsumer) Programmatically create a Flux by generating signals one-by-one via a consumer callback and some state, with a final cleanup callback.
static <T> Flux<T>	generate(Consumer<SynchronousSink<T>> generator) Programmatically create a Flux by generating signals one-by-one via a consumer callback.
int	getPrefetch() The prefetch configuration of the Flux
<K> Flux<GroupedFlux<K,T>>	groupBy(Function<? super T,? extends K> keyMapper) Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function.
<K,V> Flux<GroupedFlux<K,V>>	groupBy(Function<? super T,? extends K> keyMapper, Function<? super T,? extends V> valueMapper) Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function.
<K,V> Flux<GroupedFlux<K,V>>	groupBy(Function<? super T,? extends K> keyMapper, Function<? super T,? extends V> valueMapper, int prefetch) Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function.
<K> Flux<GroupedFlux<K,T>>	groupBy(Function<? super T,? extends K> keyMapper, int prefetch) Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function.
<TRight,TLeftEnd,TRightEnd,R> Flux<R>	groupJoin(Publisher<? extends TRight> other, Function<? super T,? extends Publisher<TLeftEnd>> leftEnd, Function<? super TRight,? extends Publisher<TRightEnd>> rightEnd, BiFunction<? super T,? super Flux<TRight>,? extends R> resultSelector) Map values from two Publishers into time windows and emit combination of values in case their windows overlap.
<R> Flux<R>	handle(BiConsumer<? super T,SynchronousSink<R>> handler) Handle the items emitted by this Flux by calling a biconsumer with the output sink for each onNext.
Mono<Boolean>	hasElement(T value) Emit a single boolean true if any of the elements of this Flux sequence is equal to the provided value.
Mono<Boolean>	hasElements() Emit a single boolean true if this Flux sequence has at least one element.
Flux<T>	hide() Hides the identities of this Flux instance.
Mono<T>	ignoreElements() Ignores onNext signals (dropping them) and only propagate termination events.
Flux<Tuple2<Long,T>>	index() Keep information about the order in which source values were received by indexing them with a 0-based incrementing long, returning a Flux of Tuple2<(index, value)>.
<I> Flux<I>	index(BiFunction<? super Long,? super T,? extends I> indexMapper) Keep information about the order in which source values were received by indexing them internally with a 0-based incrementing long then combining this information with the source value into a I using the provided BiFunction, returning a Flux<I>.
static Flux<Long>	interval(Duration period) Create a Flux that emits long values starting with 0 and incrementing at specified time intervals on the global timer.
static Flux<Long>	interval(Duration delay, Duration period) Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, after an initial delay, on the global timer.
static Flux<Long>	interval(Duration delay, Duration period, Scheduler timer) Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, after an initial delay, on the specified Scheduler.
static Flux<Long>	interval(Duration period, Scheduler timer) Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, on the specified Scheduler.
<TRight,TLeftEnd,TRightEnd,R> Flux<R>	join(Publisher<? extends TRight> other, Function<? super T,? extends Publisher<TLeftEnd>> leftEnd, Function<? super TRight,? extends Publisher<TRightEnd>> rightEnd, BiFunction<? super T,? super TRight,? extends R> resultSelector) Map values from two Publishers into time windows and emit combination of values in case their windows overlap.
static <T> Flux<T>	just(T... data) Create a Flux that emits the provided elements and then completes.
static <T> Flux<T>	just(T data) Create a new Flux that will only emit a single element then onComplete.
Mono<T>	last() Emit the last element observed before complete signal as a Mono, or emit NoSuchElementException error if the source was empty.
Mono<T>	last(T defaultValue) Emit the last element observed before complete signal as a Mono, or emit the defaultValue if the source was empty.
Flux<T>	limitRate(int prefetchRate) Ensure that backpressure signals from downstream subscribers are split into batches capped at the provided prefetchRate when propagated upstream, effectively rate limiting the upstream Publisher.
Flux<T>	limitRate(int highTide, int lowTide) Ensure that backpressure signals from downstream subscribers are split into batches capped at the provided highTide first, then replenishing at the provided lowTide, effectively rate limiting the upstream Publisher.
Flux<T>	limitRequest(long requestCap) Ensure that the total amount requested upstream is capped at cap.
Flux<T>	log() Observe all Reactive Streams signals and trace them using Logger support.
Flux<T>	log(Logger logger) Observe Reactive Streams signals matching the passed filter options and trace them using a specific user-provided Logger, at Level.INFO level.
Flux<T>	log(Logger logger, Level level, boolean showOperatorLine, SignalType... options) Observe Reactive Streams signals matching the passed filter options and trace them using a specific user-provided Logger, at the given Level.
Flux<T>	log(String category) Observe all Reactive Streams signals and trace them using Logger support.
Flux<T>	log(String category, Level level, boolean showOperatorLine, SignalType... options) Observe Reactive Streams signals matching the passed filter options and trace them using Logger support.
Flux<T>	log(String category, Level level, SignalType... options) Observe Reactive Streams signals matching the passed filter options and trace them using Logger support.
<V> Flux<V>	map(Function<? super T,? extends V> mapper) Transform the items emitted by this Flux by applying a synchronous function to each item.
Flux<Signal<T>>	materialize() Transform incoming onNext, onError and onComplete signals into Signal instances, materializing these signals.
static <I> Flux<I>	merge(int prefetch, Publisher<? extends I>... sources) Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence.
static <I> Flux<I>	merge(Iterable<? extends Publisher<? extends I>> sources) Merge data from Publisher sequences contained in an Iterable into an interleaved merged sequence.
static <I> Flux<I>	merge(Publisher<? extends I>... sources) Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence.
static <T> Flux<T>	merge(Publisher<? extends Publisher<? extends T>> source) Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence.
static <T> Flux<T>	merge(Publisher<? extends Publisher<? extends T>> source, int concurrency) Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence.
static <T> Flux<T>	merge(Publisher<? extends Publisher<? extends T>> source, int concurrency, int prefetch) Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence.
static <I> Flux<I>	mergeDelayError(int prefetch, Publisher<? extends I>... sources) Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence.
static <T> Flux<T>	mergeOrdered(Comparator<? super T> comparator, Publisher<? extends T>... sources) Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by the provided Comparator).
static <T> Flux<T>	mergeOrdered(int prefetch, Comparator<? super T> comparator, Publisher<? extends T>... sources) Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by the provided Comparator).
static <I extends Comparable<? super I>> Flux<I>	mergeOrdered(Publisher<? extends I>... sources) Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by their natural order).
Flux<T>	mergeOrderedWith(Publisher<? extends T> other, Comparator<? super T> otherComparator) Merge data from this Flux and a Publisher into a reordered merge sequence, by picking the smallest value from each sequence as defined by a provided Comparator.
static <I> Flux<I>	mergeSequential(int prefetch, Publisher<? extends I>... sources) Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence.
static <I> Flux<I>	mergeSequential(Iterable<? extends Publisher<? extends I>> sources) Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence.
static <I> Flux<I>	mergeSequential(Iterable<? extends Publisher<? extends I>> sources, int maxConcurrency, int prefetch) Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence.
static <I> Flux<I>	mergeSequential(Publisher<? extends I>... sources) Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence.
static <T> Flux<T>	mergeSequential(Publisher<? extends Publisher<? extends T>> sources) Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence.
static <T> Flux<T>	mergeSequential(Publisher<? extends Publisher<? extends T>> sources, int maxConcurrency, int prefetch) Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence.
static <I> Flux<I>	mergeSequentialDelayError(int prefetch, Publisher<? extends I>... sources) Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence.
static <I> Flux<I>	mergeSequentialDelayError(Iterable<? extends Publisher<? extends I>> sources, int maxConcurrency, int prefetch) Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence.
static <T> Flux<T>	mergeSequentialDelayError(Publisher<? extends Publisher<? extends T>> sources, int maxConcurrency, int prefetch) Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence.
Flux<T>	mergeWith(Publisher<? extends T> other) Merge data from this Flux and a Publisher into an interleaved merged sequence.
Flux<T>	name(String name) Give a name to this sequence, which can be retrieved using Scannable.name() as long as this is the first reachable Scannable.parents().
static <T> Flux<T>	never() Create a Flux that will never signal any data, error or completion signal.
Mono<T>	next() Emit only the first item emitted by this Flux, into a new Mono.
<U> Flux<U>	ofType(Class<U> clazz) Evaluate each accepted value against the given Class type.
protected static <T> ConnectableFlux<T>	onAssembly(ConnectableFlux<T> source) To be used by custom operators: invokes assembly Hooks pointcut given a ConnectableFlux, potentially returning a new ConnectableFlux.
protected static <T> Flux<T>	onAssembly(Flux<T> source) To be used by custom operators: invokes assembly Hooks pointcut given a Flux, potentially returning a new Flux.
Flux<T>	onBackpressureBuffer() Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream.
Flux<T>	onBackpressureBuffer(Duration ttl, int maxSize, Consumer<? super T> onBufferEviction) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit and for a maximum Duration of ttl (as measured on the elastic Scheduler).
Flux<T>	onBackpressureBuffer(Duration ttl, int maxSize, Consumer<? super T> onBufferEviction, Scheduler scheduler) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit and for a maximum Duration of ttl (as measured on the provided Scheduler).
Flux<T>	onBackpressureBuffer(int maxSize) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream.
Flux<T>	onBackpressureBuffer(int maxSize, BufferOverflowStrategy bufferOverflowStrategy) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit.
Flux<T>	onBackpressureBuffer(int maxSize, Consumer<? super T> onOverflow) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream.
Flux<T>	onBackpressureBuffer(int maxSize, Consumer<? super T> onBufferOverflow, BufferOverflowStrategy bufferOverflowStrategy) Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit.
Flux<T>	onBackpressureDrop() Request an unbounded demand and push to the returned Flux, or drop the observed elements if not enough demand is requested downstream.
Flux<T>	onBackpressureDrop(Consumer<? super T> onDropped) Request an unbounded demand and push to the returned Flux, or drop and notify dropping Consumer with the observed elements if not enough demand is requested downstream.
Flux<T>	onBackpressureError() Request an unbounded demand and push to the returned Flux, or emit onError fom Exceptions.failWithOverflow() if not enough demand is requested downstream.
Flux<T>	onBackpressureLatest() Request an unbounded demand and push to the returned Flux, or only keep the most recent observed item if not enough demand is requested downstream.
<E extends Throwable> Flux<T>	onErrorMap(Class<E> type, Function<? super E,? extends Throwable> mapper) Transform an error emitted by this Flux by synchronously applying a function to it if the error matches the given type.
Flux<T>	onErrorMap(Function<? super Throwable,? extends Throwable> mapper) Transform any error emitted by this Flux by synchronously applying a function to it.
Flux<T>	onErrorMap(Predicate<? super Throwable> predicate, Function<? super Throwable,? extends Throwable> mapper) Transform an error emitted by this Flux by synchronously applying a function to it if the error matches the given predicate.
<E extends Throwable> Flux<T>	onErrorResume(Class<E> type, Function<? super E,? extends Publisher<? extends T>> fallback) Subscribe to a fallback publisher when an error matching the given type occurs, using a function to choose the fallback depending on the error.
Flux<T>	onErrorResume(Function<? super Throwable,? extends Publisher<? extends T>> fallback) Subscribe to a returned fallback publisher when any error occurs, using a function to choose the fallback depending on the error.
Flux<T>	onErrorResume(Predicate<? super Throwable> predicate, Function<? super Throwable,? extends Publisher<? extends T>> fallback) Subscribe to a fallback publisher when an error matching a given predicate occurs.
<E extends Throwable> Flux<T>	onErrorReturn(Class<E> type, T fallbackValue) Simply emit a captured fallback value when an error of the specified type is observed on this Flux.
Flux<T>	onErrorReturn(Predicate<? super Throwable> predicate, T fallbackValue) Simply emit a captured fallback value when an error matching the given predicate is observed on this Flux.
Flux<T>	onErrorReturn(T fallbackValue) Simply emit a captured fallback value when any error is observed on this Flux.
protected static <T> Flux<T>	onLastAssembly(Flux<T> source) To be used by custom operators: invokes assembly Hooks pointcut given a Flux, potentially returning a new Flux.
Flux<T>	onTerminateDetach() Detaches both the child Subscriber and the Subscription on termination or cancellation.
Flux<T>	or(Publisher<? extends T> other) Pick the first Publisher between this Flux and another publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.
ParallelFlux<T>	parallel() Prepare this Flux by dividing data on a number of 'rails' matching the number of CPU cores, in a round-robin fashion.
ParallelFlux<T>	parallel(int parallelism) Prepare this Flux by dividing data on a number of 'rails' matching the provided parallelism parameter, in a round-robin fashion.
ParallelFlux<T>	parallel(int parallelism, int prefetch) Prepare this Flux by dividing data on a number of 'rails' matching the provided parallelism parameter, in a round-robin fashion and using a custom prefetch amount and queue for dealing with the source Flux's values.
ConnectableFlux<T>	publish() Prepare a ConnectableFlux which shares this Flux sequence and dispatches values to subscribers in a backpressure-aware manner.
<R> Flux<R>	publish(Function<? super Flux<T>,? extends Publisher<? extends R>> transform) Shares a sequence for the duration of a function that may transform it and consume it as many times as necessary without causing multiple subscriptions to the upstream.
<R> Flux<R>	publish(Function<? super Flux<T>,? extends Publisher<? extends R>> transform, int prefetch) Shares a sequence for the duration of a function that may transform it and consume it as many times as necessary without causing multiple subscriptions to the upstream.
ConnectableFlux<T>	publish(int prefetch) Prepare a ConnectableFlux which shares this Flux sequence and dispatches values to subscribers in a backpressure-aware manner.
Mono<T>	publishNext() Prepare a Mono which shares this Flux sequence and dispatches the first observed item to subscribers in a backpressure-aware manner.
Flux<T>	publishOn(Scheduler scheduler) Run onNext, onComplete and onError on a supplied Scheduler Worker.
Flux<T>	publishOn(Scheduler scheduler, boolean delayError, int prefetch) Run onNext, onComplete and onError on a supplied Scheduler Scheduler.Worker.
Flux<T>	publishOn(Scheduler scheduler, int prefetch) Run onNext, onComplete and onError on a supplied Scheduler Scheduler.Worker.
static <T> Flux<T>	push(Consumer<? super FluxSink<T>> emitter) Programmatically create a Flux with the capability of emitting multiple elements from a single-threaded producer through the FluxSink API.
static <T> Flux<T>	push(Consumer<? super FluxSink<T>> emitter, FluxSink.OverflowStrategy backpressure) Programmatically create a Flux with the capability of emitting multiple elements from a single-threaded producer through the FluxSink API.
static Flux<Integer>	range(int start, int count) Build a Flux that will only emit a sequence of count incrementing integers, starting from start.
<A> Mono<A>	reduce(A initial, BiFunction<A,? super T,A> accumulator) Reduce the values from this Flux sequence into an single object matching the type of a seed value.
Mono<T>	reduce(BiFunction<T,T,T> aggregator) Reduce the values from this Flux sequence into an single object of the same type than the emitted items.
<A> Mono<A>	reduceWith(Supplier<A> initial, BiFunction<A,? super T,A> accumulator) Reduce the values from this Flux sequence into an single object matching the type of a lazily supplied seed value.
Flux<T>	repeat() Repeatedly and indefinitely subscribe to the source upon completion of the previous subscription.
Flux<T>	repeat(BooleanSupplier predicate) Repeatedly subscribe to the source if the predicate returns true after completion of the previous subscription.
Flux<T>	repeat(long numRepeat) Repeatedly subscribe to the source numRepeat times.
Flux<T>	repeat(long numRepeat, BooleanSupplier predicate) Repeatedly subscribe to the source if the predicate returns true after completion of the previous subscription.
Flux<T>	repeatWhen(Function<Flux<Long>,? extends Publisher<?>> repeatFactory) Repeatedly subscribe to this Flux when a companion sequence emits elements in response to the flux completion signal.
ConnectableFlux<T>	replay() Turn this Flux into a hot source and cache last emitted signals for further Subscriber.
ConnectableFlux<T>	replay(Duration ttl) Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber.
ConnectableFlux<T>	replay(Duration ttl, Scheduler timer) Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber.
ConnectableFlux<T>	replay(int history) Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber.
ConnectableFlux<T>	replay(int history, Duration ttl) Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber.
ConnectableFlux<T>	replay(int history, Duration ttl, Scheduler timer) Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber.
Flux<T>	retry() Re-subscribes to this Flux sequence if it signals any error, indefinitely.
Flux<T>	retry(long numRetries) Re-subscribes to this Flux sequence if it signals any error, for a fixed number of times.
Flux<T>	retry(long numRetries, Predicate<? super Throwable> retryMatcher) Re-subscribes to this Flux sequence up to the specified number of retries if it signals any error that match the given Predicate, otherwise push the error downstream.
Flux<T>	retry(Predicate<? super Throwable> retryMatcher) Re-subscribes to this Flux sequence if it signals any error that matches the given Predicate, otherwise push the error downstream.
Flux<T>	retryWhen(Function<Flux<Throwable>,? extends Publisher<?>> whenFactory) Retries this Flux when a companion sequence signals an item in response to this Flux error signal
Flux<T>	sample(Duration timespan) Sample this Flux by periodically emitting an item corresponding to that Flux latest emitted value within the periodical time window.
<U> Flux<T>	sample(Publisher<U> sampler) Sample this Flux by emitting an item corresponding to that Flux latest emitted value whenever a companion sampler Publisher signals a value.
Flux<T>	sampleFirst(Duration timespan) Repeatedly take a value from this Flux then skip the values that follow within a given duration.
<U> Flux<T>	sampleFirst(Function<? super T,? extends Publisher<U>> samplerFactory) Repeatedly take a value from this Flux then skip the values that follow before the next signal from a companion sampler Publisher.
<U> Flux<T>	sampleTimeout(Function<? super T,? extends Publisher<U>> throttlerFactory) Emit the latest value from this Flux only if there were no new values emitted during the window defined by a companion Publisher derived from that particular value.
<U> Flux<T>	sampleTimeout(Function<? super T,? extends Publisher<U>> throttlerFactory, int maxConcurrency) Emit the latest value from this Flux only if there were no new values emitted during the window defined by a companion Publisher derived from that particular value.
<A> Flux<A>	scan(A initial, BiFunction<A,? super T,A> accumulator) Reduce this Flux values with an accumulator BiFunction and also emit the intermediate results of this function.
Flux<T>	scan(BiFunction<T,T,T> accumulator) Reduce this Flux values with an accumulator BiFunction and also emit the intermediate results of this function.
<A> Flux<A>	scanWith(Supplier<A> initial, BiFunction<A,? super T,A> accumulator) Reduce this Flux values with the help of an accumulator BiFunction and also emits the intermediate results.
Flux<T>	share() Returns a new Flux that multicasts (shares) the original Flux.
Mono<T>	single() Expect and emit a single item from this Flux source or signal NoSuchElementException for an empty source, or IndexOutOfBoundsException for a source with more than one element.
Mono<T>	single(T defaultValue) Expect and emit a single item from this Flux source and emit a default value for an empty source, but signal an IndexOutOfBoundsException for a source with more than one element.
Mono<T>	singleOrEmpty() Expect and emit a single item from this Flux source, and accept an empty source but signal an IndexOutOfBoundsException for a source with more than one element.
Flux<T>	skip(Duration timespan) Skip elements from this Flux emitted within the specified initial duration.
Flux<T>	skip(Duration timespan, Scheduler timer) Skip elements from this Flux emitted within the specified initial duration, as measured on the provided Scheduler.
Flux<T>	skip(long skipped) Skip the specified number of elements from the beginning of this Flux then emit the remaining elements.
Flux<T>	skipLast(int n) Skip a specified number of elements at the end of this Flux sequence.
Flux<T>	skipUntil(Predicate<? super T> untilPredicate) Skips values from this Flux until a Predicate returns true for the value.
Flux<T>	skipUntilOther(Publisher<?> other) Skip values from this Flux until a specified Publisher signals an onNext or onComplete.
Flux<T>	skipWhile(Predicate<? super T> skipPredicate) Skips values from this Flux while a Predicate returns true for the value.
Flux<T>	sort() Sort elements from this Flux by collecting and sorting them in the background then emitting the sorted sequence once this sequence completes.
Flux<T>	sort(Comparator<? super T> sortFunction) Sort elements from this Flux using a Comparator function, by collecting and sorting elements in the background then emitting the sorted sequence once this sequence completes.
Flux<T>	startWith(Iterable<? extends T> iterable) Prepend the given Iterable before this Flux sequence.
Flux<T>	startWith(Publisher<? extends T> publisher) Prepend the given Publisher sequence to this Flux sequence.
Flux<T>	startWith(T... values) Prepend the given values before this Flux sequence.
Disposable	subscribe() Subscribe to this Flux and request unbounded demand.
Disposable	subscribe(Consumer<? super T> consumer) Subscribe a Consumer to this Flux that will consume all the elements in the sequence.
Disposable	subscribe(Consumer<? super T> consumer, Consumer<? super Throwable> errorConsumer) Subscribe to this Flux with a Consumer that will consume all the elements in the sequence, as well as a Consumer that will handle errors.
Disposable	subscribe(Consumer<? super T> consumer, Consumer<? super Throwable> errorConsumer, Runnable completeConsumer) Subscribe Consumer to this Flux that will respectively consume all the elements in the sequence, handle errors and react to completion.
Disposable	subscribe(Consumer<? super T> consumer, Consumer<? super Throwable> errorConsumer, Runnable completeConsumer, Consumer<? super Subscription> subscriptionConsumer) Subscribe Consumer to this Flux that will respectively consume all the elements in the sequence, handle errors, react to completion, and request upon subscription.
abstract void	subscribe(CoreSubscriber<? super T> actual) An internal Publisher.subscribe(Subscriber) that will bypass Hooks.onLastOperator(Function) pointcut.
void	subscribe(Subscriber<? super T> actual)
Flux<T>	subscribeOn(Scheduler scheduler) Run subscribe, onSubscribe and request on a specified Scheduler's Scheduler.Worker.
Flux<T>	subscribeOn(Scheduler scheduler, boolean requestOnSeparateThread) Run subscribe and onSubscribe on a specified Scheduler's Scheduler.Worker.
Flux<T>	subscriberContext(Context mergeContext) Enrich a potentially empty downstream Context by adding all values from the given Context, producing a new Context that is propagated upstream.
Flux<T>	subscriberContext(Function<Context,Context> doOnContext) Enrich a potentially empty downstream Context by applying a Function to it, producing a new Context that is propagated upstream.
<E extends Subscriber<? super T>> E	subscribeWith(E subscriber) Subscribe the given Subscriber to this Flux and return said Subscriber (eg.
Flux<T>	switchIfEmpty(Publisher<? extends T> alternate) Switch to an alternative Publisher if this sequence is completed without any data.
<V> Flux<V>	switchMap(Function<? super T,Publisher<? extends V>> fn) Switch to a new Publisher generated via a Function whenever this Flux produces an item.
<V> Flux<V>	switchMap(Function<? super T,Publisher<? extends V>> fn, int prefetch) Switch to a new Publisher generated via a Function whenever this Flux produces an item.
static <T> Flux<T>	switchOnNext(Publisher<? extends Publisher<? extends T>> mergedPublishers) Creates a Flux that mirrors the most recently emitted Publisher, forwarding its data until a new Publisher comes in in the source.
static <T> Flux<T>	switchOnNext(Publisher<? extends Publisher<? extends T>> mergedPublishers, int prefetch) Creates a Flux that mirrors the most recently emitted Publisher, forwarding its data until a new Publisher comes in in the source.
Flux<T>	tag(String key, String value) Tag this flux with a key/value pair.
Flux<T>	take(Duration timespan) Relay values from this Flux until the specified Duration elapses.
Flux<T>	take(Duration timespan, Scheduler timer) Relay values from this Flux until the specified Duration elapses, as measured on the specified Scheduler.
Flux<T>	take(long n) Take only the first N values from this Flux, if available.
Flux<T>	takeLast(int n) Emit the last N values this Flux emitted before its completion.
Flux<T>	takeUntil(Predicate<? super T> predicate) Relay values from this Flux until the given Predicate matches.
Flux<T>	takeUntilOther(Publisher<?> other) Relay values from this Flux until the given Publisher emits.
Flux<T>	takeWhile(Predicate<? super T> continuePredicate) Relay values from this Flux while a predicate returns TRUE for the values (checked before each value is delivered).
Mono<Void>	then() Return a Mono<Void> that completes when this Flux completes.
<V> Mono<V>	then(Mono<V> other) Let this Flux complete then play signals from a provided Mono.
Mono<Void>	thenEmpty(Publisher<Void> other) Return a Mono<Void> that waits for this Flux to complete then for a supplied Publisher<Void> to also complete.
<V> Flux<V>	thenMany(Publisher<V> other) Let this Flux complete then play another Publisher.
Flux<T>	timeout(Duration timeout) Propagate a TimeoutException as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item).
Flux<T>	timeout(Duration timeout, Publisher<? extends T> fallback) Switch to a fallback Flux as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item).
Flux<T>	timeout(Duration timeout, Publisher<? extends T> fallback, Scheduler timer) Switch to a fallback Flux as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item), as measured on the specified Scheduler.
Flux<T>	timeout(Duration timeout, Scheduler timer) Propagate a TimeoutException as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item), as measured by the specified Scheduler.
<U> Flux<T>	timeout(Publisher<U> firstTimeout) Signal a TimeoutException in case the first item from this Flux has not been emitted before the given Publisher emits.
<U,V> Flux<T>	timeout(Publisher<U> firstTimeout, Function<? super T,? extends Publisher<V>> nextTimeoutFactory) Signal a TimeoutException in case the first item from this Flux has not been emitted before the firstTimeout Publisher emits, and whenever each subsequent elements is not emitted before a Publisher generated from the latest element signals.
<U,V> Flux<T>	timeout(Publisher<U> firstTimeout, Function<? super T,? extends Publisher<V>> nextTimeoutFactory, Publisher<? extends T> fallback) Switch to a fallback Publisher in case the first item from this Flux has not been emitted before the firstTimeout Publisher emits, and whenever each subsequent elements is not emitted before a Publisher generated from the latest element signals.
Flux<Tuple2<Long,T>>	timestamp() Emit a Tuple2 pair of T1 the current clock time in millis (as a Long measured by the parallel Scheduler) and T2 the emitted data (as a T), for each item from this Flux.
Flux<Tuple2<Long,T>>	timestamp(Scheduler scheduler) Emit a Tuple2 pair of T1 the current clock time in millis (as a Long measured by the provided Scheduler) and T2 the emitted data (as a T), for each item from this Flux.
Iterable<T>	toIterable() Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.
Iterable<T>	toIterable(int batchSize) Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.
Iterable<T>	toIterable(int batchSize, Supplier<Queue<T>> queueProvider) Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.
Stream<T>	toStream() Transform this Flux into a lazy Stream blocking for each source onNext call.
Stream<T>	toStream(int batchSize) Transform this Flux into a lazy Stream blocking for each source onNext call.
String	toString()
<V> Flux<V>	transform(Function<? super Flux<T>,? extends Publisher<V>> transformer) Transform this Flux in order to generate a target Flux.
static <T,D> Flux<T>	using(Callable<? extends D> resourceSupplier, Function<? super D,? extends Publisher<? extends T>> sourceSupplier, Consumer<? super D> resourceCleanup) Uses a resource, generated by a supplier for each individual Subscriber, while streaming the values from a Publisher derived from the same resource and makes sure the resource is released if the sequence terminates or the Subscriber cancels.
static <T,D> Flux<T>	using(Callable<? extends D> resourceSupplier, Function<? super D,? extends Publisher<? extends T>> sourceSupplier, Consumer<? super D> resourceCleanup, boolean eager) Uses a resource, generated by a supplier for each individual Subscriber, while streaming the values from a Publisher derived from the same resource and makes sure the resource is released if the sequence terminates or the Subscriber cancels.
Flux<Flux<T>>	window(Duration timespan) Split this Flux sequence into continuous, non-overlapping windows that open for a timespan Duration (as measured on the parallel Scheduler).
Flux<Flux<T>>	window(Duration timespan, Duration timeshift) Split this Flux sequence into multiple Flux windows that open for a given timespan Duration, after which it closes with onComplete.
Flux<Flux<T>>	window(Duration timespan, Duration timeshift, Scheduler timer) Split this Flux sequence into multiple Flux windows that open for a given timespan Duration, after which it closes with onComplete.
Flux<Flux<T>>	window(Duration timespan, Scheduler timer) Split this Flux sequence into continuous, non-overlapping windows that open for a timespan Duration (as measured on the provided Scheduler).
Flux<Flux<T>>	window(int maxSize) Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item.
Flux<Flux<T>>	window(int maxSize, int skip) Split this Flux sequence into multiple Flux windows of size maxSize, that each open every skip elements in the source.
Flux<Flux<T>>	window(Publisher<?> boundary) Split this Flux sequence into continuous, non-overlapping windows where the window boundary is signalled by another Publisher
Flux<Flux<T>>	windowTimeout(int maxSize, Duration timespan) Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item.
Flux<Flux<T>>	windowTimeout(int maxSize, Duration timespan, Scheduler timer) Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item.
Flux<Flux<T>>	windowUntil(Predicate<T> boundaryTrigger) Split this Flux sequence into multiple Flux windows delimited by the given predicate.
Flux<Flux<T>>	windowUntil(Predicate<T> boundaryTrigger, boolean cutBefore) Split this Flux sequence into multiple Flux windows delimited by the given predicate.
Flux<Flux<T>>	windowUntil(Predicate<T> boundaryTrigger, boolean cutBefore, int prefetch) Split this Flux sequence into multiple Flux windows delimited by the given predicate and using a prefetch.
<U,V> Flux<Flux<T>>	windowWhen(Publisher<U> bucketOpening, Function<? super U,? extends Publisher<V>> closeSelector) Split this Flux sequence into potentially overlapping windows controlled by items of a start Publisher and end Publisher derived from the start values.
Flux<Flux<T>>	windowWhile(Predicate<T> inclusionPredicate) Split this Flux sequence into multiple Flux windows that stay open while a given predicate matches the source elements.
Flux<Flux<T>>	windowWhile(Predicate<T> inclusionPredicate, int prefetch) Split this Flux sequence into multiple Flux windows that stay open while a given predicate matches the source elements.
<U,R> Flux<R>	withLatestFrom(Publisher<? extends U> other, BiFunction<? super T,? super U,? extends R> resultSelector) Combine the most recently emitted values from both this Flux and another Publisher through a BiFunction and emits the result.
static <I,O> Flux<O>	zip(Function<? super Object[],? extends O> combinator, int prefetch, Publisher<? extends I>... sources) Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <I,O> Flux<O>	zip(Function<? super Object[],? extends O> combinator, Publisher<? extends I>... sources) Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <O> Flux<O>	zip(Iterable<? extends Publisher<?>> sources, Function<? super Object[],? extends O> combinator) Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <O> Flux<O>	zip(Iterable<? extends Publisher<?>> sources, int prefetch, Function<? super Object[],? extends O> combinator) Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <TUPLE extends Tuple2,V> Flux<V>	zip(Publisher<? extends Publisher<?>> sources, Function<? super TUPLE,? extends V> combinator) Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <T1,T2> Flux<Tuple2<T1,T2>>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2) Zip two sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple2.
static <T1,T2,O> Flux<O>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2, BiFunction<? super T1,? super T2,? extends O> combinator) Zip two sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator).
static <T1,T2,T3> Flux<Tuple3<T1,T2,T3>>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3) Zip three sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple3.
static <T1,T2,T3,T4> Flux<Tuple4<T1,T2,T3,T4>>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4) Zip four sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple4.
static <T1,T2,T3,T4,T5> Flux<Tuple5<T1,T2,T3,T4,T5>>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4, Publisher<? extends T5> source5) Zip five sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple5.
static <T1,T2,T3,T4,T5,T6> Flux<Tuple6<T1,T2,T3,T4,T5,T6>>	zip(Publisher<? extends T1> source1, Publisher<? extends T2> source2, Publisher<? extends T3> source3, Publisher<? extends T4> source4, Publisher<? extends T5> source5, Publisher<? extends T6> source6) Zip six sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple6.
<T2> Flux<Tuple2<T,T2>>	zipWith(Publisher<? extends T2> source2) Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements once into a Tuple2.
<T2,V> Flux<V>	zipWith(Publisher<? extends T2> source2, BiFunction<? super T,? super T2,? extends V> combinator) Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements using a combinator BiFunction The operator will continue doing so until any of the sources completes.
<T2> Flux<Tuple2<T,T2>>	zipWith(Publisher<? extends T2> source2, int prefetch) Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements once into a Tuple2.
<T2,V> Flux<V>	zipWith(Publisher<? extends T2> source2, int prefetch, BiFunction<? super T,? super T2,? extends V> combinator) Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements using a combinator BiFunction The operator will continue doing so until any of the sources completes.
<T2> Flux<Tuple2<T,T2>>	zipWithIterable(Iterable<? extends T2> iterable) Zip elements from this Flux with the content of an Iterable, that is to say combine one element from each, pairwise, into a Tuple2.
<T2,V> Flux<V>	zipWithIterable(Iterable<? extends T2> iterable, BiFunction<? super T,? super T2,? extends V> zipper) Zip elements from this Flux with the content of an Iterable, that is to say combine one element from each, pairwise, using the given zipper BiFunction.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Flux

public Flux()

Method Detail

combineLatest

@SafeVarargs
public static <T,V> Flux<V> combineLatest(Function<Object[],V> combinator,
                                                       Publisher<? extends T>... sources)

Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources.

Type Parameters:

T - type of the value from sources

V - The produced output after transformation by the given combinator

Parameters:

sources - The Publisher sources to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

@SafeVarargs
public static <T,V> Flux<V> combineLatest(Function<Object[],V> combinator,
                                                       int prefetch,
                                                       Publisher<? extends T>... sources)

Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources.

Type Parameters:

T - type of the value from sources

V - The produced output after transformation by the given combinator

Parameters:

sources - The Publisher sources to combine values from

prefetch - The demand sent to each combined source Publisher

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T1,T2,V> Flux<V> combineLatest(Publisher<? extends T1> source1,
                                              Publisher<? extends T2> source2,
                                              BiFunction<? super T1,? super T2,? extends V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of two Publisher sources.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

V - The produced output after transformation by the given combinator

Parameters:

source1 - The first Publisher source to combine values from

source2 - The second Publisher source to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T1,T2,T3,V> Flux<V> combineLatest(Publisher<? extends T1> source1,
                                                 Publisher<? extends T2> source2,
                                                 Publisher<? extends T3> source3,
                                                 Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of three Publisher sources.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

V - The produced output after transformation by the given combinator

Parameters:

source1 - The first Publisher source to combine values from

source2 - The second Publisher source to combine values from

source3 - The third Publisher source to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T1,T2,T3,T4,V> Flux<V> combineLatest(Publisher<? extends T1> source1,
                                                    Publisher<? extends T2> source2,
                                                    Publisher<? extends T3> source3,
                                                    Publisher<? extends T4> source4,
                                                    Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of four Publisher sources.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

V - The produced output after transformation by the given combinator

Parameters:

source1 - The first Publisher source to combine values from

source2 - The second Publisher source to combine values from

source3 - The third Publisher source to combine values from

source4 - The fourth Publisher source to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T1,T2,T3,T4,T5,V> Flux<V> combineLatest(Publisher<? extends T1> source1,
                                                       Publisher<? extends T2> source2,
                                                       Publisher<? extends T3> source3,
                                                       Publisher<? extends T4> source4,
                                                       Publisher<? extends T5> source5,
                                                       Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of five Publisher sources.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

T5 - type of the value from source5

V - The produced output after transformation by the given combinator

Parameters:

source1 - The first Publisher source to combine values from

source2 - The second Publisher source to combine values from

source3 - The third Publisher source to combine values from

source4 - The fourth Publisher source to combine values from

source5 - The fifth Publisher source to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T1,T2,T3,T4,T5,T6,V> Flux<V> combineLatest(Publisher<? extends T1> source1,
                                                          Publisher<? extends T2> source2,
                                                          Publisher<? extends T3> source3,
                                                          Publisher<? extends T4> source4,
                                                          Publisher<? extends T5> source5,
                                                          Publisher<? extends T6> source6,
                                                          Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of six Publisher sources.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

T5 - type of the value from source5

T6 - type of the value from source6

V - The produced output after transformation by the given combinator

Parameters:

source1 - The first Publisher source to combine values from

source2 - The second Publisher source to combine values from

source3 - The third Publisher source to combine values from

source4 - The fourth Publisher source to combine values from

source5 - The fifth Publisher source to combine values from

source6 - The sixth Publisher source to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T,V> Flux<V> combineLatest(Iterable<? extends Publisher<? extends T>> sources,
                                          Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources provided in an Iterable.

Type Parameters:

T - The common base type of the values from sources

V - The produced output after transformation by the given combinator

Parameters:

sources - The list of Publisher sources to combine values from

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

combineLatest

public static <T,V> Flux<V> combineLatest(Iterable<? extends Publisher<? extends T>> sources,
                                          int prefetch,
                                          Function<Object[],V> combinator)

Build a Flux whose data are generated by the combination of the most recently published value from each of the Publisher sources provided in an Iterable.

Type Parameters:

T - The common base type of the values from sources

V - The produced output after transformation by the given combinator

Parameters:

sources - The list of Publisher sources to combine values from

prefetch - demand produced to each combined source Publisher

combinator - The aggregate function that will receive the latest value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced combinations

concat

public static <T> Flux<T> concat(Iterable<? extends Publisher<? extends T>> sources)

Concatenate all sources provided in an Iterable, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Any error interrupts the sequence immediately and is forwarded downstream.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Iterable of Publisher to concatenate

Returns:

a new Flux concatenating all source sequences

concatWithValues

@SafeVarargs
public final Flux<T> concatWithValues(T... values)

Concatenates the values to the end of the Flux

Parameters:

values - The values to concatenate

Returns:

a new Flux concatenating all source sequences

concat

public static <T> Flux<T> concat(Publisher<? extends Publisher<? extends T>> sources)

Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Any error interrupts the sequence immediately and is forwarded downstream.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concatenate

Returns:

a new Flux concatenating all inner sources sequences

concat

public static <T> Flux<T> concat(Publisher<? extends Publisher<? extends T>> sources,
                                 int prefetch)

Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Any error interrupts the sequence immediately and is forwarded downstream.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concatenate

prefetch - the inner source request size

Returns:

a new Flux concatenating all inner sources sequences

concat

@SafeVarargs
public static <T> Flux<T> concat(Publisher<? extends T>... sources)

Concatenate all sources provided as a vararg, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Any error interrupts the sequence immediately and is forwarded downstream.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concat

Returns:

a new Flux concatenating all source sequences

concatDelayError

public static <T> Flux<T> concatDelayError(Publisher<? extends Publisher<? extends T>> sources)

Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Errors do not interrupt the main sequence but are propagated after the rest of the sources have had a chance to be concatenated.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concatenate

Returns:

a new Flux concatenating all inner sources sequences, delaying errors

concatDelayError

public static <T> Flux<T> concatDelayError(Publisher<? extends Publisher<? extends T>> sources,
                                           int prefetch)

Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Errors do not interrupt the main sequence but are propagated after the rest of the sources have had a chance to be concatenated.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concatenate

prefetch - the inner source request size

Returns:

a new Flux concatenating all inner sources sequences until complete or error

concatDelayError

public static <T> Flux<T> concatDelayError(Publisher<? extends Publisher<? extends T>> sources,
                                           boolean delayUntilEnd,
                                           int prefetch)

Concatenate all sources emitted as an onNext signal from a parent Publisher, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes.

Errors do not interrupt the main sequence but are propagated after the current concat backlog if delayUntilEnd is false or after all sources have had a chance to be concatenated if delayUntilEnd is true.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concatenate

delayUntilEnd - delay error until all sources have been consumed instead of after the current source

prefetch - the inner source request size

Returns:

a new Flux concatenating all inner sources sequences until complete or error

concatDelayError

@SafeVarargs
public static <T> Flux<T> concatDelayError(Publisher<? extends T>... sources)

Concatenate all sources provided as a vararg, forwarding elements emitted by the sources downstream.

Concatenation is achieved by sequentially subscribing to the first source then waiting for it to complete before subscribing to the next, and so on until the last source completes. Errors do not interrupt the main sequence but are propagated after the rest of the sources have had a chance to be concatenated.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

sources - The Publisher of Publisher to concat

Returns:

a new Flux concatenating all source sequences

create

public static <T> Flux<T> create(Consumer<? super FluxSink<T>> emitter)

Programmatically create a Flux with the capability of emitting multiple elements in a synchronous or asynchronous manner through the FluxSink API.

This Flux factory is useful if one wants to adapt some other multi-valued async API and not worry about cancellation and backpressure (which is handled by buffering all signals if the downstream can't keep up).

For example:

 Flux.<String>create(emitter -> {

     ActionListener al = e -> {
         emitter.next(textField.getText());
     };
     // without cleanup support:

     button.addActionListener(al);

     // with cleanup support:

     button.addActionListener(al);
     emitter.onDispose(() -> {
         button.removeListener(al);
     });
 });
 

Type Parameters:

T - The type of values in the sequence

Parameters:

emitter - Consume the FluxSink provided per-subscriber by Reactor to generate signals.

Returns:

a Flux

create

public static <T> Flux<T> create(Consumer<? super FluxSink<T>> emitter,
                                 FluxSink.OverflowStrategy backpressure)

Programmatically create a Flux with the capability of emitting multiple elements in a synchronous or asynchronous manner through the FluxSink API.

This Flux factory is useful if one wants to adapt some other multi-valued async API and not worry about cancellation and backpressure (which is handled by buffering all signals if the downstream can't keep up).

For example:

 Flux.<String>create(emitter -> {

     ActionListener al = e -> {
         emitter.next(textField.getText());
     };
     // without cleanup support:

     button.addActionListener(al);

     // with cleanup support:

     button.addActionListener(al);
     emitter.onDispose(() -> {
         button.removeListener(al);
     });
 }, FluxSink.OverflowStrategy.LATEST);
 

Type Parameters:

T - The type of values in the sequence

Parameters:

backpressure - the backpressure mode, see FluxSink.OverflowStrategy for the available backpressure modes

emitter - Consume the FluxSink provided per-subscriber by Reactor to generate signals.

Returns:

a Flux

push

public static <T> Flux<T> push(Consumer<? super FluxSink<T>> emitter)

Programmatically create a Flux with the capability of emitting multiple elements from a single-threaded producer through the FluxSink API.

This Flux factory is useful if one wants to adapt some other single-threaded multi-valued async API and not worry about cancellation and backpressure (which is handled by buffering all signals if the downstream can't keep up).

For example:

 Flux.<String>push(emitter -> {

         ActionListener al = e -> {
                 emitter.next(textField.getText());
         };
         // without cleanup support:

         button.addActionListener(al);

         // with cleanup support:

         button.addActionListener(al);
         emitter.onDispose(() -> {
                 button.removeListener(al);
         });
 }, FluxSink.OverflowStrategy.LATEST);
 

Type Parameters:

T - The type of values in the sequence

Parameters:

emitter - Consume the FluxSink provided per-subscriber by Reactor to generate signals.

Returns:

a Flux

push

public static <T> Flux<T> push(Consumer<? super FluxSink<T>> emitter,
                               FluxSink.OverflowStrategy backpressure)

Programmatically create a Flux with the capability of emitting multiple elements from a single-threaded producer through the FluxSink API.

This Flux factory is useful if one wants to adapt some other single-threaded multi-valued async API and not worry about cancellation and backpressure (which is handled by buffering all signals if the downstream can't keep up).

For example:

 Flux.<String>push(emitter -> {

         ActionListener al = e -> {
                 emitter.next(textField.getText());
         };
         // without cleanup support:

         button.addActionListener(al);

         // with cleanup support:

         button.addActionListener(al);
         emitter.onDispose(() -> {
                 button.removeListener(al);
         });
 }, FluxSink.OverflowStrategy.LATEST);
 

Type Parameters:

T - The type of values in the sequence

Parameters:

backpressure - the backpressure mode, see FluxSink.OverflowStrategy for the available backpressure modes

emitter - Consume the FluxSink provided per-subscriber by Reactor to generate signals.

Returns:

a Flux

defer

public static <T> Flux<T> defer(Supplier<? extends Publisher<T>> supplier)

Lazily supply a Publisher every time a Subscription is made on the resulting Flux, so the actual source instantiation is deferred until each subscribe and the Supplier can create a subscriber-specific instance. If the supplier doesn't generate a new instance however, this operator will effectively behave like from(Publisher).

Type Parameters:

T - the type of values passing through the Flux

Parameters:

supplier - the Publisher Supplier to call on subscribe

Returns:

a deferred Flux

empty

public static <T> Flux<T> empty()

Create a Flux that completes without emitting any item.

Type Parameters:

T - the reified type of the target Subscriber

Returns:

an empty Flux

error

public static <T> Flux<T> error(Throwable error)

Create a Flux that terminates with the specified error immediately after being subscribed to.

Type Parameters:

T - the reified type of the target Subscriber

Parameters:

error - the error to signal to each Subscriber

Returns:

a new failed Flux

error

public static <O> Flux<O> error(Throwable throwable,
                                boolean whenRequested)

Create a Flux that terminates with the specified error, either immediately after being subscribed to or after being first requested.

Type Parameters:

O - the reified type of the target Subscriber

Parameters:

throwable - the error to signal to each Subscriber

whenRequested - if true, will onError on the first request instead of subscribe().

Returns:

a new failed Flux

first

@SafeVarargs
public static <I> Flux<I> first(Publisher<? extends I>... sources)

Pick the first Publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.

Type Parameters:

I - The type of values in both source and output sequences

Parameters:

sources - The competing source publishers

Returns:

a new Flux behaving like the fastest of its sources

first

public static <I> Flux<I> first(Iterable<? extends Publisher<? extends I>> sources)

Pick the first Publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.

Type Parameters:

I - The type of values in both source and output sequences

Parameters:

sources - The competing source publishers

Returns:

a new Flux behaving like the fastest of its sources

from

public static <T> Flux<T> from(Publisher<? extends T> source)

Decorate the specified Publisher with the Flux API.

Type Parameters:

T - The type of values in both source and output sequences

Parameters:

source - the source to decorate

Returns:

a new Flux

fromArray

public static <T> Flux<T> fromArray(T[] array)

Create a Flux that emits the items contained in the provided array.

Type Parameters:

T - The type of values in the source array and resulting Flux

Parameters:

array - the array to read data from

Returns:

a new Flux

fromIterable

public static <T> Flux<T> fromIterable(Iterable<? extends T> it)

Create a Flux that emits the items contained in the provided Iterable. A new iterator will be created for each subscriber.

Type Parameters:

T - The type of values in the source Iterable and resulting Flux

Parameters:

it - the Iterable to read data from

Returns:

a new Flux

fromStream

public static <T> Flux<T> fromStream(Stream<? extends T> s)

Create a Flux that emits the items contained in the provided Stream. Keep in mind that a Stream cannot be re-used, which can be problematic in case of multiple subscriptions or re-subscription (like with repeat() or retry()). The Stream is closed automatically by the operator on cancellation, error or completion.

Type Parameters:

T - The type of values in the source Stream and resulting Flux

Parameters:

s - the Stream to read data from

Returns:

a new Flux

fromStream

public static <T> Flux<T> fromStream(Supplier<Stream<? extends T>> streamSupplier)

Create a Flux that emits the items contained in a Stream created by the provided Supplier for each subscription. The Stream is closed automatically by the operator on cancellation, error or completion.

Type Parameters:

T - The type of values in the source Stream and resulting Flux

Parameters:

streamSupplier - the Supplier that generates the Stream from which to read data

Returns:

a new Flux

generate

public static <T> Flux<T> generate(Consumer<SynchronousSink<T>> generator)

Programmatically create a Flux by generating signals one-by-one via a consumer callback.

Type Parameters:

T - the value type emitted

Parameters:

generator - Consume the SynchronousSink provided per-subscriber by Reactor to generate a single signal on each pass.

Returns:

a Flux

generate

public static <T,S> Flux<T> generate(Callable<S> stateSupplier,
                                     BiFunction<S,SynchronousSink<T>,S> generator)

Programmatically create a Flux by generating signals one-by-one via a consumer callback and some state. The stateSupplier may return null.

Type Parameters:

T - the value type emitted

S - the per-subscriber custom state type

Parameters:

stateSupplier - called for each incoming Subscriber to provide the initial state for the generator bifunction

generator - Consume the SynchronousSink provided per-subscriber by Reactor as well as the current state to generate a single signal on each pass and return a (new) state.

Returns:

a Flux

generate

public static <T,S> Flux<T> generate(Callable<S> stateSupplier,
                                     BiFunction<S,SynchronousSink<T>,S> generator,
                                     Consumer<? super S> stateConsumer)

Programmatically create a Flux by generating signals one-by-one via a consumer callback and some state, with a final cleanup callback. The stateSupplier may return null but your cleanup stateConsumer will need to handle the null case.

Type Parameters:

T - the value type emitted

S - the per-subscriber custom state type

Parameters:

stateSupplier - called for each incoming Subscriber to provide the initial state for the generator bifunction

generator - Consume the SynchronousSink provided per-subscriber by Reactor as well as the current state to generate a single signal on each pass and return a (new) state.

stateConsumer - called after the generator has terminated or the downstream cancelled, receiving the last state to be handled (i.e., release resources or do other cleanup).

Returns:

a Flux

interval

public static Flux<Long> interval(Duration period)

Create a Flux that emits long values starting with 0 and incrementing at specified time intervals on the global timer. If demand is not produced in time, an onError will be signalled with an overflow IllegalStateException detailing the tick that couldn't be emitted. In normal conditions, the Flux will never complete.

Runs on the Schedulers.parallel() Scheduler.

Parameters:

period - the period Duration between each increment

Returns:

a new Flux emitting increasing numbers at regular intervals

interval

public static Flux<Long> interval(Duration delay,
                                  Duration period)

Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, after an initial delay, on the global timer. If demand is not produced in time, an onError will be signalled with an overflow IllegalStateException detailing the tick that couldn't be emitted. In normal conditions, the Flux will never complete.

Runs on the Schedulers.parallel() Scheduler.

Parameters:

delay - the Duration to wait before emitting 0l

period - the period Duration before each following increment

Returns:

a new Flux emitting increasing numbers at regular intervals

interval

public static Flux<Long> interval(Duration period,
                                  Scheduler timer)

Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, on the specified Scheduler. If demand is not produced in time, an onError will be signalled with an overflow IllegalStateException detailing the tick that couldn't be emitted. In normal conditions, the Flux will never complete.

Parameters:

period - the period Duration between each increment

timer - a time-capable Scheduler instance to run on

Returns:

a new Flux emitting increasing numbers at regular intervals

interval

public static Flux<Long> interval(Duration delay,
                                  Duration period,
                                  Scheduler timer)

Create a Flux that emits long values starting with 0 and incrementing at specified time intervals, after an initial delay, on the specified Scheduler. If demand is not produced in time, an onError will be signalled with an overflow IllegalStateException detailing the tick that couldn't be emitted. In normal conditions, the Flux will never complete.

Parameters:

delay - the Duration to wait before emitting 0l

period - the period Duration before each following increment

timer - a time-capable Scheduler instance to run on

Returns:

a new Flux emitting increasing numbers at regular intervals

just

@SafeVarargs
public static <T> Flux<T> just(T... data)

Create a Flux that emits the provided elements and then completes.

Type Parameters:

T - the emitted data type

Parameters:

data - the elements to emit, as a vararg

Returns:

a new Flux

just

public static <T> Flux<T> just(T data)

Create a new Flux that will only emit a single element then onComplete.

Type Parameters:

T - the emitted data type

Parameters:

data - the single element to emit

Returns:

a new Flux

merge

public static <T> Flux<T> merge(Publisher<? extends Publisher<? extends T>> source)

Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence. Unlike concat, inner sources are subscribed to eagerly.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

T - the merged type

Parameters:

source - a Publisher of Publisher sources to merge

Returns:

a merged Flux

merge

public static <T> Flux<T> merge(Publisher<? extends Publisher<? extends T>> source,
                                int concurrency)

Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence. Unlike concat, inner sources are subscribed to eagerly (but at most concurrency sources are subscribed to at the same time).

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

T - the merged type

Parameters:

source - a Publisher of Publisher sources to merge

concurrency - the request produced to the main source thus limiting concurrent merge backlog

Returns:

a merged Flux

merge

public static <T> Flux<T> merge(Publisher<? extends Publisher<? extends T>> source,
                                int concurrency,
                                int prefetch)

Merge data from Publisher sequences emitted by the passed Publisher into an interleaved merged sequence. Unlike concat, inner sources are subscribed to eagerly (but at most concurrency sources are subscribed to at the same time).

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

T - the merged type

Parameters:

source - a Publisher of Publisher sources to merge

concurrency - the request produced to the main source thus limiting concurrent merge backlog

prefetch - the inner source request size

Returns:

a merged Flux

merge

public static <I> Flux<I> merge(Iterable<? extends Publisher<? extends I>> sources)

Merge data from Publisher sequences contained in an Iterable into an interleaved merged sequence. Unlike concat, inner sources are subscribed to eagerly. A new Iterator will be created for each subscriber.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

I - The source type of the data sequence

Parameters:

sources - the Iterable of sources to merge (will be lazily iterated on subscribe)

Returns:

a merged Flux

merge

@SafeVarargs
public static <I> Flux<I> merge(Publisher<? extends I>... sources)

Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence. Unlike concat, sources are subscribed to eagerly.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

I - The source type of the data sequence

Parameters:

sources - the array of Publisher sources to merge

Returns:

a merged Flux

merge

@SafeVarargs
public static <I> Flux<I> merge(int prefetch,
                                             Publisher<? extends I>... sources)

Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence. Unlike concat, sources are subscribed to eagerly.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

I - The source type of the data sequence

Parameters:

sources - the array of Publisher sources to merge

prefetch - the inner source request size

Returns:

a fresh Reactive Flux publisher ready to be subscribed

mergeDelayError

@SafeVarargs
public static <I> Flux<I> mergeDelayError(int prefetch,
                                                       Publisher<? extends I>... sources)

Merge data from Publisher sequences contained in an array / vararg into an interleaved merged sequence. Unlike concat, sources are subscribed to eagerly. This variant will delay any error until after the rest of the merge backlog has been processed.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Type Parameters:

I - The source type of the data sequence

Parameters:

sources - the array of Publisher sources to merge

prefetch - the inner source request size

Returns:

a fresh Reactive Flux publisher ready to be subscribed

mergeOrdered

@SafeVarargs
public static <I extends Comparable<? super I>> Flux<I> mergeOrdered(Publisher<? extends I>... sources)

Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by their natural order). This is not a sort(), as it doesn't consider the whole of each sequences.

Instead, this operator considers only one value from each source and picks the smallest of all these values, then replenishes the slot for that picked source.

Type Parameters:

I - a Comparable merged type that has a natural order

Parameters:

sources - Publisher sources of Comparable to merge

Returns:

a merged Flux that , subscribing early but keeping the original ordering

mergeOrdered

@SafeVarargs
public static <T> Flux<T> mergeOrdered(Comparator<? super T> comparator,
                                                    Publisher<? extends T>... sources)

Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by the provided Comparator). This is not a sort(Comparator), as it doesn't consider the whole of each sequences.

Instead, this operator considers only one value from each source and picks the smallest of all these values, then replenishes the slot for that picked source.

Type Parameters:

T - the merged type

Parameters:

comparator - the Comparator to use to find the smallest value

sources - Publisher sources to merge

Returns:

a merged Flux that , subscribing early but keeping the original ordering

mergeOrdered

@SafeVarargs
public static <T> Flux<T> mergeOrdered(int prefetch,
                                                    Comparator<? super T> comparator,
                                                    Publisher<? extends T>... sources)

Merge data from provided Publisher sequences into an ordered merged sequence, by picking the smallest values from each source (as defined by the provided Comparator). This is not a sort(Comparator), as it doesn't consider the whole of each sequences.

Instead, this operator considers only one value from each source and picks the smallest of all these values, then replenishes the slot for that picked source.

Type Parameters:

T - the merged type

Parameters:

prefetch - the number of elements to prefetch from each source (avoiding too many small requests to the source when picking)

comparator - the Comparator to use to find the smallest value

sources - Publisher sources to merge

Returns:

a merged Flux that , subscribing early but keeping the original ordering

mergeSequential

public static <T> Flux<T> mergeSequential(Publisher<? extends Publisher<? extends T>> sources)

Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence. Unlike concat, the inner publishers are subscribed to eagerly. Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

T - the merged type

Parameters:

sources - a Publisher of Publisher sources to merge

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequential

public static <T> Flux<T> mergeSequential(Publisher<? extends Publisher<? extends T>> sources,
                                          int maxConcurrency,
                                          int prefetch)

Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence. Unlike concat, the inner publishers are subscribed to eagerly (but at most maxConcurrency sources at a time). Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

T - the merged type

Parameters:

sources - a Publisher of Publisher sources to merge

prefetch - the inner source request size

maxConcurrency - the request produced to the main source thus limiting concurrent merge backlog

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequentialDelayError

public static <T> Flux<T> mergeSequentialDelayError(Publisher<? extends Publisher<? extends T>> sources,
                                                    int maxConcurrency,
                                                    int prefetch)

Merge data from Publisher sequences emitted by the passed Publisher into an ordered merged sequence. Unlike concat, the inner publishers are subscribed to eagerly (but at most maxConcurrency sources at a time). Unlike merge, their emitted values are merged into the final sequence in subscription order. This variant will delay any error until after the rest of the mergeSequential backlog has been processed.

Type Parameters:

T - the merged type

Parameters:

sources - a Publisher of Publisher sources to merge

prefetch - the inner source request size

maxConcurrency - the request produced to the main source thus limiting concurrent merge backlog

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequential

@SafeVarargs
public static <I> Flux<I> mergeSequential(Publisher<? extends I>... sources)

Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly. Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

I - the merged type

Parameters:

sources - a number of Publisher sequences to merge

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequential

@SafeVarargs
public static <I> Flux<I> mergeSequential(int prefetch,
                                                       Publisher<? extends I>... sources)

Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly. Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

I - the merged type

Parameters:

prefetch - the inner source request size

sources - a number of Publisher sequences to merge

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequentialDelayError

@SafeVarargs
public static <I> Flux<I> mergeSequentialDelayError(int prefetch,
                                                                 Publisher<? extends I>... sources)

Merge data from Publisher sequences provided in an array/vararg into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly. Unlike merge, their emitted values are merged into the final sequence in subscription order. This variant will delay any error until after the rest of the mergeSequential backlog has been processed.

Type Parameters:

I - the merged type

Parameters:

prefetch - the inner source request size

sources - a number of Publisher sequences to merge

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequential

public static <I> Flux<I> mergeSequential(Iterable<? extends Publisher<? extends I>> sources)

Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly. Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

I - the merged type

Parameters:

sources - an Iterable of Publisher sequences to merge

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequential

public static <I> Flux<I> mergeSequential(Iterable<? extends Publisher<? extends I>> sources,
                                          int maxConcurrency,
                                          int prefetch)

Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly (but at most maxConcurrency sources at a time). Unlike merge, their emitted values are merged into the final sequence in subscription order.

Type Parameters:

I - the merged type

Parameters:

sources - an Iterable of Publisher sequences to merge

maxConcurrency - the request produced to the main source thus limiting concurrent merge backlog

prefetch - the inner source request size

Returns:

a merged Flux, subscribing early but keeping the original ordering

mergeSequentialDelayError

public static <I> Flux<I> mergeSequentialDelayError(Iterable<? extends Publisher<? extends I>> sources,
                                                    int maxConcurrency,
                                                    int prefetch)

Merge data from Publisher sequences provided in an Iterable into an ordered merged sequence. Unlike concat, sources are subscribed to eagerly (but at most maxConcurrency sources at a time). Unlike merge, their emitted values are merged into the final sequence in subscription order. This variant will delay any error until after the rest of the mergeSequential backlog has been processed.

Type Parameters:

I - the merged type

Parameters:

sources - an Iterable of Publisher sequences to merge

maxConcurrency - the request produced to the main source thus limiting concurrent merge backlog

prefetch - the inner source request size

Returns:

a merged Flux, subscribing early but keeping the original ordering

never

public static <T> Flux<T> never()

Create a Flux that will never signal any data, error or completion signal.

Type Parameters:

T - the Subscriber type target

Returns:

a never completing Flux

range

public static Flux<Integer> range(int start,
                                  int count)

Build a Flux that will only emit a sequence of count incrementing integers, starting from start. That is, emit integers between start (included) and start + count (excluded) then complete.

Parameters:

start - the first integer to be emit

count - the total number of incrementing values to emit, including the first value

Returns:

a ranged Flux

switchOnNext

public static <T> Flux<T> switchOnNext(Publisher<? extends Publisher<? extends T>> mergedPublishers)

Creates a Flux that mirrors the most recently emitted Publisher, forwarding its data until a new Publisher comes in in the source.

The resulting Flux will complete once there are no new Publisher in the source (source has completed) and the last mirrored Publisher has also completed.

Type Parameters:

T - the produced type

Parameters:

mergedPublishers - The Publisher of Publisher to switch on and mirror.

Returns:

a FluxProcessor accepting publishers and producing T

switchOnNext

public static <T> Flux<T> switchOnNext(Publisher<? extends Publisher<? extends T>> mergedPublishers,
                                       int prefetch)

Creates a Flux that mirrors the most recently emitted Publisher, forwarding its data until a new Publisher comes in in the source.

The resulting Flux will complete once there are no new Publisher in the source (source has completed) and the last mirrored Publisher has also completed.

Type Parameters:

T - the produced type

Parameters:

mergedPublishers - The Publisher of Publisher to switch on and mirror.

prefetch - the inner source request size

Returns:

a FluxProcessor accepting publishers and producing T

using

public static <T,D> Flux<T> using(Callable<? extends D> resourceSupplier,
                                  Function<? super D,? extends Publisher<? extends T>> sourceSupplier,
                                  Consumer<? super D> resourceCleanup)

Uses a resource, generated by a supplier for each individual Subscriber, while streaming the values from a Publisher derived from the same resource and makes sure the resource is released if the sequence terminates or the Subscriber cancels.

Eager resource cleanup happens just before the source termination and exceptions raised by the cleanup Consumer may override the terminal even.

Type Parameters:

T - emitted type

D - resource type

Parameters:

resourceSupplier - a Callable that is called on subscribe to generate the resource

sourceSupplier - a factory to derive a Publisher from the supplied resource

resourceCleanup - a resource cleanup callback invoked on completion

Returns:

a new Flux built around a disposable resource

using

public static <T,D> Flux<T> using(Callable<? extends D> resourceSupplier,
                                  Function<? super D,? extends Publisher<? extends T>> sourceSupplier,
                                  Consumer<? super D> resourceCleanup,
                                  boolean eager)

Uses a resource, generated by a supplier for each individual Subscriber, while streaming the values from a Publisher derived from the same resource and makes sure the resource is released if the sequence terminates or the Subscriber cancels.

• Eager resource cleanup happens just before the source termination and exceptions raised by the cleanup Consumer may override the terminal even.
• Non-eager cleanup will drop any exception.

Type Parameters:

T - emitted type

D - resource type

Parameters:

resourceSupplier - a Callable that is called on subscribe to generate the resource

sourceSupplier - a factory to derive a Publisher from the supplied resource

resourceCleanup - a resource cleanup callback invoked on completion

eager - true to clean before terminating downstream subscribers

Returns:

a new Flux built around a disposable resource

zip

public static <T1,T2,O> Flux<O> zip(Publisher<? extends T1> source1,
                                    Publisher<? extends T2> source2,
                                    BiFunction<? super T1,? super T2,? extends O> combinator)

Zip two sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

O - The produced output after transformation by the combinator

Parameters:

source1 - The first Publisher source to zip.

source2 - The second Publisher source to zip.

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

Returns:

a zipped Flux

zip

public static <T1,T2> Flux<Tuple2<T1,T2>> zip(Publisher<? extends T1> source1,
                                              Publisher<? extends T2> source2)

Zip two sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple2. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

Parameters:

source1 - The first Publisher source to zip.

source2 - The second Publisher source to zip.

Returns:

a zipped Flux

zip

public static <T1,T2,T3> Flux<Tuple3<T1,T2,T3>> zip(Publisher<? extends T1> source1,
                                                    Publisher<? extends T2> source2,
                                                    Publisher<? extends T3> source3)

Zip three sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple3. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

Parameters:

source1 - The first upstream Publisher to subscribe to.

source2 - The second upstream Publisher to subscribe to.

source3 - The third upstream Publisher to subscribe to.

Returns:

a zipped Flux

zip

public static <T1,T2,T3,T4> Flux<Tuple4<T1,T2,T3,T4>> zip(Publisher<? extends T1> source1,
                                                          Publisher<? extends T2> source2,
                                                          Publisher<? extends T3> source3,
                                                          Publisher<? extends T4> source4)

Zip four sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple4. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

Parameters:

source1 - The first upstream Publisher to subscribe to.

source2 - The second upstream Publisher to subscribe to.

source3 - The third upstream Publisher to subscribe to.

source4 - The fourth upstream Publisher to subscribe to.

Returns:

a zipped Flux

zip

public static <T1,T2,T3,T4,T5> Flux<Tuple5<T1,T2,T3,T4,T5>> zip(Publisher<? extends T1> source1,
                                                                Publisher<? extends T2> source2,
                                                                Publisher<? extends T3> source3,
                                                                Publisher<? extends T4> source4,
                                                                Publisher<? extends T5> source5)

Zip five sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple5. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

T5 - type of the value from source5

Parameters:

source1 - The first upstream Publisher to subscribe to.

source2 - The second upstream Publisher to subscribe to.

source3 - The third upstream Publisher to subscribe to.

source4 - The fourth upstream Publisher to subscribe to.

source5 - The fifth upstream Publisher to subscribe to.

Returns:

a zipped Flux

zip

public static <T1,T2,T3,T4,T5,T6> Flux<Tuple6<T1,T2,T3,T4,T5,T6>> zip(Publisher<? extends T1> source1,
                                                                      Publisher<? extends T2> source2,
                                                                      Publisher<? extends T3> source3,
                                                                      Publisher<? extends T4> source4,
                                                                      Publisher<? extends T5> source5,
                                                                      Publisher<? extends T6> source6)

Zip six sources together, that is to say wait for all the sources to emit one element and combine these elements once into a Tuple6. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T1 - type of the value from source1

T2 - type of the value from source2

T3 - type of the value from source3

T4 - type of the value from source4

T5 - type of the value from source5

T6 - type of the value from source6

Parameters:

source1 - The first upstream Publisher to subscribe to.

source2 - The second upstream Publisher to subscribe to.

source3 - The third upstream Publisher to subscribe to.

source4 - The fourth upstream Publisher to subscribe to.

source5 - The fifth upstream Publisher to subscribe to.

source6 - The sixth upstream Publisher to subscribe to.

Returns:

a zipped Flux

zip

public static <O> Flux<O> zip(Iterable<? extends Publisher<?>> sources,
                              Function<? super Object[],? extends O> combinator)

Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios. The Iterable.iterator() will be called on each Publisher.subscribe(Subscriber).

Type Parameters:

O - the combined produced type

Parameters:

sources - the Iterable providing sources to zip

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

Returns:

a zipped Flux

zip

public static <O> Flux<O> zip(Iterable<? extends Publisher<?>> sources,
                              int prefetch,
                              Function<? super Object[],? extends O> combinator)

Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios. The Iterable.iterator() will be called on each Publisher.subscribe(Subscriber).

Type Parameters:

O - the combined produced type

Parameters:

sources - the Iterable providing sources to zip

prefetch - the inner source request size

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

Returns:

a zipped Flux

zip

@SafeVarargs
public static <I,O> Flux<O> zip(Function<? super Object[],? extends O> combinator,
                                             Publisher<? extends I>... sources)

Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

I - the type of the input sources

O - the combined produced type

Parameters:

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

sources - the array providing sources to zip

Returns:

a zipped Flux

zip

@SafeVarargs
public static <I,O> Flux<O> zip(Function<? super Object[],? extends O> combinator,
                                             int prefetch,
                                             Publisher<? extends I>... sources)

Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

I - the type of the input sources

O - the combined produced type

Parameters:

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

prefetch - individual source request size

sources - the array providing sources to zip

Returns:

a zipped Flux

zip

public static <TUPLE extends Tuple2,V> Flux<V> zip(Publisher<? extends Publisher<?>> sources,
                                                   Function<? super TUPLE,? extends V> combinator)

Zip multiple sources together, that is to say wait for all the sources to emit one element and combine these elements once into an output value (constructed by the provided combinator). The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Note that the Publisher sources from the outer Publisher will accumulate into an exhaustive list before starting zip operation.

Type Parameters:

TUPLE - the raw tuple type

V - The produced output after transformation by the given combinator

Parameters:

sources - The Publisher of Publisher sources to zip. A finite publisher is required.

combinator - The aggregate function that will receive a unique value from each upstream and return the value to signal downstream

Returns:

a Flux based on the produced value

all

public final Mono<Boolean> all(Predicate<? super T> predicate)

Emit a single boolean true if all values of this sequence match the Predicate.

The implementation uses short-circuit logic and completes with false if the predicate doesn't match a value.

Parameters:

predicate - the Predicate that needs to apply to all emitted items

Returns:

a new Mono with true if all values satisfies a predicate and false otherwise

any

public final Mono<Boolean> any(Predicate<? super T> predicate)

Emit a single boolean true if any of the values of this Flux sequence match the predicate.

The implementation uses short-circuit logic and completes with false if any value doesn't match the predicate.

Parameters:

predicate - the Predicate that needs to apply to at least one emitted item

Returns:

a new Mono with true if any value satisfies a predicate and false otherwise

as

public final <P> P as(Function<? super Flux<T>,P> transformer)

Transform this Flux into a target type.

  flux.as(Mono::from).subscribe() 
 

Type Parameters:

P - the returned instance type

Parameters:

transformer - the Function to immediately map this Flux into a target type instance.

Returns:

the Flux transformed to an instance of P

See Also:

for a bounded conversion to {@link Publisher}

blockFirst

@Nullable
public final T blockFirst()

Subscribe to this Flux and block indefinitely until the upstream signals its first value or completes. Returns that value, or null if the Flux completes empty. In case the Flux errors, the original exception is thrown (wrapped in a RuntimeException if it was a checked exception).

Note that each blockFirst() will trigger a new subscription: in other words, the result might miss signal from hot publishers.

Returns:

the first value or null

blockFirst

@Nullable
public final T blockFirst(Duration timeout)

Subscribe to this Flux and block until the upstream signals its first value, completes or a timeout expires. Returns that value, or null if the Flux completes empty. In case the Flux errors, the original exception is thrown (wrapped in a RuntimeException if it was a checked exception). If the provided timeout expires,a RuntimeException is thrown.

Note that each blockFirst() will trigger a new subscription: in other words, the result might miss signal from hot publishers.

Parameters:

timeout - maximum time period to wait for before raising a RuntimeException

Returns:

the first value or null

blockLast

@Nullable
public final T blockLast()

Subscribe to this Flux and block indefinitely until the upstream signals its last value or completes. Returns that value, or null if the Flux completes empty. In case the Flux errors, the original exception is thrown (wrapped in a RuntimeException if it was a checked exception).

Note that each blockLast() will trigger a new subscription: in other words, the result might miss signal from hot publishers.

Returns:

the last value or null

blockLast

@Nullable
public final T blockLast(Duration timeout)

Subscribe to this Flux and block until the upstream signals its last value, completes or a timeout expires. Returns that value, or null if the Flux completes empty. In case the Flux errors, the original exception is thrown (wrapped in a RuntimeException if it was a checked exception). If the provided timeout expires,a RuntimeException is thrown.

Note that each blockLast() will trigger a new subscription: in other words, the result might miss signal from hot publishers.

Parameters:

timeout - maximum time period to wait for before raising a RuntimeException

Returns:

the last value or null

buffer

public final Flux<List<T>> buffer()

Collect all incoming values into a single List buffer that will be emitted by the returned Flux once this Flux completes.

Returns:

a buffered Flux of at most one List

See Also:

for an alternative collecting algorithm returning {@link Mono}

buffer

public final Flux<List<T>> buffer(int maxSize)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.

Parameters:

maxSize - the maximum collected size

Returns:

a microbatched Flux of List

buffer

public final <C extends Collection<? super T>> Flux<C> buffer(int maxSize,
                                                              Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes.

Type Parameters:

C - the Collection buffer type

Parameters:

maxSize - the maximum collected size

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of Collection

buffer

public final Flux<List<T>> buffer(int maxSize,
                                  int skip)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes. Buffers can be created with gaps, as a new buffer will be created every time skip values have been emitted by the source.

When maxSize < skip : dropping buffers

When maxSize > skip : overlapping buffers

When maxSize == skip : exact buffers

Parameters:

skip - the number of items to count before creating a new buffer

maxSize - the max collected size

Returns:

a microbatched Flux of possibly overlapped or gapped List

buffer

public final <C extends Collection<? super T>> Flux<C> buffer(int maxSize,
                                                              int skip,
                                                              Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the given max size is reached or once this Flux completes. Buffers can be created with gaps, as a new buffer will be created every time skip values have been emitted by the source

When maxSize < skip : dropping buffers

When maxSize > skip : overlapping buffers

When maxSize == skip : exact buffers

Type Parameters:

C - the Collection buffer type

Parameters:

skip - the number of items to count before creating a new buffer

maxSize - the max collected size

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of possibly overlapped or gapped Collection

buffer

public final Flux<List<T>> buffer(Publisher<?> other)

Collect incoming values into multiple List buffers, as delimited by the signals of a companion Publisher this operator will subscribe to.

Parameters:

other - the companion Publisher whose signals trigger new buffers

Returns:

a microbatched Flux of List delimited by signals from a Publisher

buffer

public final <C extends Collection<? super T>> Flux<C> buffer(Publisher<?> other,
                                                              Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers, as delimited by the signals of a companion Publisher this operator will subscribe to.

Type Parameters:

C - the Collection buffer type

Parameters:

other - the companion Publisher whose signals trigger new buffers

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of Collection delimited by signals from a Publisher

buffer

public final Flux<List<T>> buffer(Duration timespan)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux every timespan.

Parameters:

timespan - the duration from buffer creation until a buffer is closed and emitted

Returns:

a microbatched Flux of List delimited by the given time span

buffer

public final Flux<List<T>> buffer(Duration timespan,
                                  Duration timeshift)

Collect incoming values into multiple List buffers created at a given timeshift period. Each buffer will last until the timespan has elapsed, thus emitting the bucket in the resulting Flux.

When timespan < timeshift : dropping buffers

When timespan > timeshift : overlapping buffers

When timespan == timeshift : exact buffers

Parameters:

timespan - the duration from buffer creation until a buffer is closed and emitted

timeshift - the interval at which to create a new buffer

Returns:

a microbatched Flux of List delimited by the given period timeshift and sized by timespan

buffer

public final Flux<List<T>> buffer(Duration timespan,
                                  Scheduler timer)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux every timespan, as measured on the provided Scheduler.

Parameters:

timespan - the duration from buffer creation until a buffer is closed and emitted

timer - a time-capable Scheduler instance to run on

Returns:

a microbatched Flux of List delimited by the given period

buffer

public final Flux<List<T>> buffer(Duration timespan,
                                  Duration timeshift,
                                  Scheduler timer)

Collect incoming values into multiple List buffers created at a given timeshift period, as measured on the provided Scheduler. Each buffer will last until the timespan has elapsed (also measured on the scheduler), thus emitting the bucket in the resulting Flux.

When timespan < timeshift : dropping buffers

When timespan > timeshift : overlapping buffers

When timespan == timeshift : exact buffers

Parameters:

timespan - the duration from buffer creation until a buffer is closed and emitted

timeshift - the interval at which to create a new buffer

timer - a time-capable Scheduler instance to run on

Returns:

a microbatched Flux of List delimited by the given period timeshift and sized by timespan

bufferTimeout

public final Flux<List<T>> bufferTimeout(int maxSize,
                                         Duration timespan)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses.

Parameters:

maxSize - the max collected size

timespan - the timeout enforcing the release of a partial buffer

Returns:

a microbatched Flux of List delimited by given size or a given period timeout

bufferTimeout

public final <C extends Collection<? super T>> Flux<C> bufferTimeout(int maxSize,
                                                                     Duration timespan,
                                                                     Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses.

Type Parameters:

C - the Collection buffer type

Parameters:

maxSize - the max collected size

timespan - the timeout enforcing the release of a partial buffer

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of Collection delimited by given size or a given period timeout

bufferTimeout

public final Flux<List<T>> bufferTimeout(int maxSize,
                                         Duration timespan,
                                         Scheduler timer)

Collect incoming values into multiple List buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses, as measured on the provided Scheduler.

Parameters:

maxSize - the max collected size

timespan - the timeout enforcing the release of a partial buffer

timer - a time-capable Scheduler instance to run on

Returns:

a microbatched Flux of List delimited by given size or a given period timeout

bufferTimeout

public final <C extends Collection<? super T>> Flux<C> bufferTimeout(int maxSize,
                                                                     Duration timespan,
                                                                     Scheduler timer,
                                                                     Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers that will be emitted by the returned Flux each time the buffer reaches a maximum size OR the timespan Duration elapses, as measured on the provided Scheduler.

Type Parameters:

C - the Collection buffer type

Parameters:

maxSize - the max collected size

timespan - the timeout enforcing the release of a partial buffer

timer - a time-capable Scheduler instance to run on

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of Collection delimited by given size or a given period timeout

bufferUntil

public final Flux<List<T>> bufferUntil(Predicate<? super T> predicate)

Collect incoming values into multiple List buffers that will be emitted by the resulting Flux each time the given predicate returns true. Note that the element that triggers the predicate to return true (and thus closes a buffer) is included as last element in the emitted buffer.

On completion, if the latest buffer is non-empty and has not been closed it is emitted. However, such a "partial" buffer isn't emitted in case of onError termination.

Parameters:

predicate - a predicate that triggers the next buffer when it becomes true.

Returns:

a microbatched Flux of List

bufferUntil

public final Flux<List<T>> bufferUntil(Predicate<? super T> predicate,
                                       boolean cutBefore)

Collect incoming values into multiple List buffers that will be emitted by the resulting Flux each time the given predicate returns true. Note that the buffer into which the element that triggers the predicate to return true (and thus closes a buffer) is included depends on the cutBefore parameter: push it to true to include the boundary element in the newly opened buffer, false to include it in the closed buffer (as in bufferUntil(Predicate)).

On completion, if the latest buffer is non-empty and has not been closed it is emitted. However, such a "partial" buffer isn't emitted in case of onError termination.

Parameters:

predicate - a predicate that triggers the next buffer when it becomes true.

cutBefore - push to true to include the triggering element in the new buffer rather than the old.

Returns:

a microbatched Flux of List

bufferWhile

public final Flux<List<T>> bufferWhile(Predicate<? super T> predicate)

Collect incoming values into multiple List buffers that will be emitted by the resulting Flux. Each buffer continues aggregating values while the given predicate returns true, and a new buffer is created as soon as the predicate returns false... Note that the element that triggers the predicate to return false (and thus closes a buffer) is NOT included in any emitted buffer.

On completion, if the latest buffer is non-empty and has not been closed it is emitted. However, such a "partial" buffer isn't emitted in case of onError termination.

Parameters:

predicate - a predicate that triggers the next buffer when it becomes false.

Returns:

a microbatched Flux of List

bufferWhen

public final <U,V> Flux<List<T>> bufferWhen(Publisher<U> bucketOpening,
                                            Function<? super U,? extends Publisher<V>> closeSelector)

Collect incoming values into multiple List buffers started each time an opening companion Publisher emits. Each buffer will last until the corresponding closing companion Publisher emits, thus releasing the buffer to the resulting Flux.

When Open signal is strictly not overlapping Close signal : dropping buffers

When Open signal is strictly more frequent than Close signal : overlapping buffers

When Open signal is exactly coordinated with Close signal : exact buffers

Type Parameters:

U - the element type of the buffer-opening sequence

V - the element type of the buffer-closing sequence

Parameters:

bucketOpening - a companion Publisher to subscribe for buffer creation signals.

closeSelector - a factory that, given a buffer opening signal, returns a companion Publisher to subscribe to for buffer closure and emission signals.

Returns:

a microbatched Flux of List delimited by an opening Publisher and a relative closing Publisher

bufferWhen

public final <U,V,C extends Collection<? super T>> Flux<C> bufferWhen(Publisher<U> bucketOpening,
                                                                      Function<? super U,? extends Publisher<V>> closeSelector,
                                                                      Supplier<C> bufferSupplier)

Collect incoming values into multiple user-defined Collection buffers started each time an opening companion Publisher emits. Each buffer will last until the corresponding closing companion Publisher emits, thus releasing the buffer to the resulting Flux.

When Open signal is strictly not overlapping Close signal : dropping buffers

When Open signal is strictly more frequent than Close signal : overlapping buffers

When Open signal is exactly coordinated with Close signal : exact buffers

Type Parameters:

U - the element type of the buffer-opening sequence

V - the element type of the buffer-closing sequence

C - the Collection buffer type

Parameters:

bucketOpening - a companion Publisher to subscribe for buffer creation signals.

closeSelector - a factory that, given a buffer opening signal, returns a companion Publisher to subscribe to for buffer closure and emission signals.

bufferSupplier - a Supplier of the concrete Collection to use for each buffer

Returns:

a microbatched Flux of Collection delimited by an opening Publisher and a relative closing Publisher

cache

public final Flux<T> cache()

Turn this Flux into a hot source and cache last emitted signals for further Subscriber. Will retain an unbounded volume of onNext signals. Completion and Error will also be replayed.

Returns:

a replaying Flux

cache

public final Flux<T> cache(int history)

Turn this Flux into a hot source and cache last emitted signals for further Subscriber. Will retain up to the given history size onNext signals. Completion and Error will also be replayed.

Note that cache(0) will only cache the terminal signal without expiration.

Parameters:

history - number of elements retained in cache

Returns:

a replaying Flux

cache

public final Flux<T> cache(Duration ttl)

Turn this Flux into a hot source and cache last emitted signals for further Subscriber. Will retain an unbounded history but apply a per-item expiry timeout

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription.

Parameters:

ttl - Time-to-live for each cached item and post termination.

Returns:

a replaying Flux

cache

public final Flux<T> cache(int history,
                           Duration ttl)

Turn this Flux into a hot source and cache last emitted signals for further Subscriber. Will retain up to the given history size and apply a per-item expiry timeout.

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription.

Parameters:

history - number of elements retained in cache

ttl - Time-to-live for each cached item and post termination.

Returns:

a replaying Flux

cast

public final <E> Flux<E> cast(Class<E> clazz)

Cast the current Flux produced type into a target produced type.

Type Parameters:

E - the Flux output type

Parameters:

clazz - the target class to cast to

Returns:

a casted Flux

cancelOn

public final Flux<T> cancelOn(Scheduler scheduler)

Prepare this Flux so that subscribers will cancel from it on a specified Scheduler.

Parameters:

scheduler - the Scheduler to signal cancel on

Returns:

a scheduled cancel Flux

checkpoint

public final Flux<T> checkpoint()

Activate assembly tracing for this particular Flux, in case of an error upstream of the checkpoint. Tracing incurs the cost of an exception stack trace creation.

It should be placed towards the end of the reactive chain, as errors triggered downstream of it cannot be observed and augmented with assembly trace.

Returns:

the assembly tracing Flux.

checkpoint

public final Flux<T> checkpoint(String description)

Activate assembly marker for this particular Flux by giving it a description that will be reflected in the assembly traceback in case of an error upstream of the checkpoint. Note that unlike checkpoint(), this doesn't create a filled stack trace, avoiding the main cost of the operator. However, as a trade-off the description must be unique enough for the user to find out where this Flux was assembled. If you only want a generic description, and still rely on the stack trace to find the assembly site, use the checkpoint(String, boolean) variant.

It should be placed towards the end of the reactive chain, as errors triggered downstream of it cannot be observed and augmented with assembly trace.

Parameters:

description - a unique enough description to include in the light assembly traceback.

Returns:

the assembly marked Flux

checkpoint

public final Flux<T> checkpoint(@Nullable
                                String description,
                                boolean forceStackTrace)

Activate assembly tracing or the lighter assembly marking depending on the forceStackTrace option.

By setting the forceStackTrace parameter to true, activate assembly tracing for this particular Flux and give it a description that will be reflected in the assembly traceback in case of an error upstream of the checkpoint. Note that unlike checkpoint(String), this will incur the cost of an exception stack trace creation. The description could for example be a meaningful name for the assembled flux or a wider correlation ID, since the stack trace will always provide enough information to locate where this Flux was assembled.

By setting forceStackTrace to false, behaves like checkpoint(String) and is subject to the same caveat in choosing the description.

It should be placed towards the end of the reactive chain, as errors triggered downstream of it cannot be observed and augmented with assembly marker.

Parameters:

description - a description (must be unique enough if forceStackTrace is push to false).

forceStackTrace - false to make a light checkpoint without a stacktrace, true to use a stack trace.

Returns:

the assembly marked Flux.

collect

public final <E> Mono<E> collect(Supplier<E> containerSupplier,
                                 BiConsumer<E,? super T> collector)

Collect all elements emitted by this Flux into a user-defined container, by applying a collector BiConsumer taking the container and each element. The collected result will be emitted when this sequence completes.

Type Parameters:

E - the container type

Parameters:

containerSupplier - the supplier of the container instance for each Subscriber

collector - a consumer of both the container instance and the value being currently collected

Returns:

a Mono of the collected container on complete

collect

public final <R,A> Mono<R> collect(Collector<? super T,A,? extends R> collector)

Collect all elements emitted by this Flux into a container, by applying a Java 8 Stream API Collector The collected result will be emitted when this sequence completes.

Type Parameters:

A - The mutable accumulation type

R - the container type

Parameters:

collector - the Collector

Returns:

a Mono of the collected container on complete

collectList

public final Mono<List<T>> collectList()

Collect all elements emitted by this Flux into a List that is emitted by the resulting Mono when this sequence completes.

Returns:

a Mono of a List of all values from this Flux

collectMap

public final <K> Mono<Map<K,T>> collectMap(Function<? super T,? extends K> keyExtractor)

Collect all elements emitted by this Flux into a hashed Map that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function. In case several elements map to the same key, the associated value will be the most recently emitted element.

Type Parameters:

K - the type of the key extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

Returns:

a Mono of a Map of key-element pairs (only including latest element in case of key conflicts)

collectMap

public final <K,V> Mono<Map<K,V>> collectMap(Function<? super T,? extends K> keyExtractor,
                                             Function<? super T,? extends V> valueExtractor)

Collect all elements emitted by this Flux into a hashed Map that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function, and the value is extracted by the valueExtractor Function. In case several elements map to the same key, the associated value will be derived from the most recently emitted element.

Type Parameters:

K - the type of the key extracted from each source element

V - the type of the value extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

valueExtractor - a Function to map elements to a value for the Map

Returns:

a Mono of a Map of key-element pairs (only including latest element's value in case of key conflicts)

collectMap

public final <K,V> Mono<Map<K,V>> collectMap(Function<? super T,? extends K> keyExtractor,
                                             Function<? super T,? extends V> valueExtractor,
                                             Supplier<Map<K,V>> mapSupplier)

Collect all elements emitted by this Flux into a user-defined Map that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function, and the value is extracted by the valueExtractor Function. In case several elements map to the same key, the associated value will be derived from the most recently emitted element.

Type Parameters:

K - the type of the key extracted from each source element

V - the type of the value extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

valueExtractor - a Function to map elements to a value for the Map

mapSupplier - a Map factory called for each Subscriber

Returns:

a Mono of a Map of key-value pairs (only including latest element's value in case of key conflicts)

collectMultimap

public final <K> Mono<Map<K,Collection<T>>> collectMultimap(Function<? super T,? extends K> keyExtractor)

Collect all elements emitted by this Flux into a multimap that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function, and every element mapping to the same key is stored in the List associated to said key.

Type Parameters:

K - the type of the key extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

Returns:

a Mono of a Map of key-List(elements) pairs

collectMultimap

public final <K,V> Mono<Map<K,Collection<V>>> collectMultimap(Function<? super T,? extends K> keyExtractor,
                                                              Function<? super T,? extends V> valueExtractor)

Collect all elements emitted by this Flux into a multimap that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function, and every element mapping to the same key is converted by the valueExtractor Function to a value stored in the List associated to said key.

Type Parameters:

K - the type of the key extracted from each source element

V - the type of the value extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

valueExtractor - a Function to map elements to a value for the Map

Returns:

a Mono of a Map of key-List(values) pairs

collectMultimap

public final <K,V> Mono<Map<K,Collection<V>>> collectMultimap(Function<? super T,? extends K> keyExtractor,
                                                              Function<? super T,? extends V> valueExtractor,
                                                              Supplier<Map<K,Collection<V>>> mapSupplier)

Collect all elements emitted by this Flux into a user-defined multimap that is emitted by the resulting Mono when this sequence completes. The key is extracted from each element by applying the keyExtractor Function, and every element mapping to the same key is converted by the valueExtractor Function to a value stored in the Collection associated to said key.

Type Parameters:

K - the type of the key extracted from each source element

V - the type of the value extracted from each source element

Parameters:

keyExtractor - a Function to map elements to a key for the Map

valueExtractor - a Function to map elements to a value for the Map

mapSupplier - a multimap (Map of Collection) factory called for each Subscriber

Returns:

a Mono of a Map of key-Collection(values) pairs

collectSortedList

public final Mono<List<T>> collectSortedList()

Collect all elements emitted by this Flux until this sequence completes, and then sort them in natural order into a List that is emitted by the resulting Mono.

Returns:

a Mono of a sorted List of all values from this Flux, in natural order

collectSortedList

public final Mono<List<T>> collectSortedList(@Nullable
                                             Comparator<? super T> comparator)

Collect all elements emitted by this Flux until this sequence completes, and then sort them using a Comparator into a List that is emitted by the resulting Mono.

Parameters:

comparator - a Comparator to sort the items of this sequences

Returns:

a Mono of a sorted List of all values from this Flux

compose

public final <V> Flux<V> compose(Function<? super Flux<T>,? extends Publisher<V>> transformer)

Defer the transformation of this Flux in order to generate a target Flux type. A transformation will occur for each Subscriber. For instance:

  flux.compose(Mono::from).subscribe() 
 

Type Parameters:

V - the item type in the returned Publisher

Parameters:

transformer - the Function to lazily map this Flux into a target Publisher instance for each new subscriber

Returns:

a new Flux

See Also:

transform() for immmediate transformation of {@link Flux}, as() for a loose conversion to an arbitrary type

concatMap

public final <V> Flux<V> concatMap(Function<? super T,? extends Publisher<? extends V>> mapper)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.

There are three dimensions to this operator that can be compared with flatMap and flatMapSequential:

• Generation of inners and subscription: this operator waits for one inner to complete before generating the next one and subscribing to it.
• Ordering of the flattened values: this operator naturally preserves the same order as the source elements, concatenating the inners from each source element sequentially.
• Interleaving: this operator does not let values from different inners interleave (concatenation).

Errors will immediately short circuit current concat backlog.

Type Parameters:

V - the produced concatenated type

Parameters:

mapper - the function to transform this sequence of T into concatenated sequences of V

Returns:

a concatenated Flux

concatMap

public final <V> Flux<V> concatMap(Function<? super T,? extends Publisher<? extends V>> mapper,
                                   int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.

There are three dimensions to this operator that can be compared with flatMap and flatMapSequential:

• Generation of inners and subscription: this operator waits for one inner to complete before generating the next one and subscribing to it.
• Ordering of the flattened values: this operator naturally preserves the same order as the source elements, concatenating the inners from each source element sequentially.
• Interleaving: this operator does not let values from different inners interleave (concatenation).

Errors will immediately short circuit current concat backlog. The prefetch argument allows to give an arbitrary prefetch size to the inner Publisher.

Type Parameters:

V - the produced concatenated type

Parameters:

mapper - the function to transform this sequence of T into concatenated sequences of V

prefetch - the inner source produced demand

Returns:

a concatenated Flux

concatMapDelayError

public final <V> Flux<V> concatMapDelayError(Function<? super T,Publisher<? extends V>> mapper)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.

There are three dimensions to this operator that can be compared with flatMap and flatMapSequential:

• Generation of inners and subscription: this operator waits for one inner to complete before generating the next one and subscribing to it.
• Ordering of the flattened values: this operator naturally preserves the same order as the source elements, concatenating the inners from each source element sequentially.
• Interleaving: this operator does not let values from different inners interleave (concatenation).

Errors in the individual publishers will be delayed after the current concat backlog, usually stopping the sequence at the source that triggered the error.

Type Parameters:

V - the produced concatenated type

Parameters:

mapper - the function to transform this sequence of T into concatenated sequences of V

Returns:

a concatenated Flux

concatMapDelayError

public final <V> Flux<V> concatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper,
                                             int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.

There are three dimensions to this operator that can be compared with flatMap and flatMapSequential:

• Generation of inners and subscription: this operator waits for one inner to complete before generating the next one and subscribing to it.
• Ordering of the flattened values: this operator naturally preserves the same order as the source elements, concatenating the inners from each source element sequentially.
• Interleaving: this operator does not let values from different inners interleave (concatenation).

Errors in the individual publishers will be delayed after the current concat backlog, usually stopping the sequence at the source that triggered the error. The prefetch argument allows to give an arbitrary prefetch size to the inner Publisher.

Type Parameters:

V - the produced concatenated type

Parameters:

mapper - the function to transform this sequence of T into concatenated sequences of V

prefetch - the inner source produced demand

Returns:

a concatenated Flux

concatMapDelayError

public final <V> Flux<V> concatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper,
                                             boolean delayUntilEnd,
                                             int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, sequentially and preserving order using concatenation.

There are three dimensions to this operator that can be compared with flatMap and flatMapSequential:

• Generation of inners and subscription: this operator waits for one inner to complete before generating the next one and subscribing to it.
• Ordering of the flattened values: this operator naturally preserves the same order as the source elements, concatenating the inners from each source element sequentially.
• Interleaving: this operator does not let values from different inners interleave (concatenation).

Errors in the individual publishers will be delayed after the current concat backlog if delayUntilEnd is false or after all sources if delayUntilEnd is true. The prefetch argument allows to give an arbitrary prefetch size to the inner Publisher.

Type Parameters:

V - the produced concatenated type

Parameters:

mapper - the function to transform this sequence of T into concatenated sequences of V

delayUntilEnd - delay error until all sources have been consumed instead of after the current source

prefetch - the inner source produced demand

Returns:

a concatenated Flux

concatMapIterable

public final <R> Flux<R> concatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper)

Transform the items emitted by this Flux into Iterable, then flatten the elements from those by concatenating them into a single Flux.

Note that unlike flatMap(Function) and concatMap(Function), with Iterable there is no notion of eager vs lazy inner subscription. The content of the Iterables are all played sequentially. Thus flatMapIterable and concatMapIterable are equivalent offered as a discoverability improvement for users that explore the API with the concat vs flatMap expectation.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N Iterable

Returns:

a concatenation of the values from the Iterables obtained from each element in this Flux

concatMapIterable

public final <R> Flux<R> concatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper,
                                           int prefetch)

Transform the items emitted by this Flux into Iterable, then flatten the emissions from those by concatenating them into a single Flux. The prefetch argument allows to give an arbitrary prefetch size to the merged Iterable.

Note that unlike flatMap(Function) and concatMap(Function), with Iterable there is no notion of eager vs lazy inner subscription. The content of the Iterables are all played sequentially. Thus flatMapIterable and concatMapIterable are equivalent offered as a discoverability improvement for users that explore the API with the concat vs flatMap expectation.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N Iterable

prefetch - the maximum in-flight elements from each inner Iterable sequence

Returns:

a concatenation of the values from the Iterables obtained from each element in this Flux

concatWith

public final Flux<T> concatWith(Publisher<? extends T> other)

Concatenate emissions of this Flux with the provided Publisher (no interleave).

Parameters:

other - the Publisher sequence to concat after this Flux

Returns:

a concatenated Flux

count

public final Mono<Long> count()

Counts the number of values in this Flux. The count will be emitted when onComplete is observed.

Returns:

a new Mono of Long count

defaultIfEmpty

public final Flux<T> defaultIfEmpty(T defaultV)

Provide a default unique value if this sequence is completed without any data

Parameters:

defaultV - the alternate value if this sequence is empty

Returns:

a new Flux

delayElements

public final Flux<T> delayElements(Duration delay)

Delay each of this Flux elements (Subscriber.onNext(T) signals) by a given Duration. Signals are delayed and continue on the parallel default Scheduler, but empty sequences or immediate error signals are not delayed.

Parameters:

delay - duration by which to delay each Subscriber.onNext(T) signal

Returns:

a delayed Flux

See Also:

delaySubscription to introduce a delay at the beginning of the sequence only

delayElements

public final Flux<T> delayElements(Duration delay,
                                   Scheduler timer)

Delay each of this Flux elements (Subscriber.onNext(T) signals) by a given Duration. Signals are delayed and continue on an user-specified Scheduler, but empty sequences or immediate error signals are not delayed.

Parameters:

delay - period to delay each Subscriber.onNext(T) signal

timer - a time-capable Scheduler instance to delay each signal on

Returns:

a delayed Flux

delaySequence

public final Flux<T> delaySequence(Duration delay)

Shift this Flux forward in time by a given Duration. Unlike with delayElements(Duration), elements are shifted forward in time as they are emitted, always resulting in the delay between two elements being the same as in the source (only the first element is visibly delayed from the previous event, that is the subscription). Signals are delayed and continue on the parallel Scheduler, but empty sequences or immediate error signals are not delayed.

With this operator, a source emitting at 10Hz with a delaySequence Duration of 1s will still emit at 10Hz, with an initial "hiccup" of 1s. On the other hand, delayElements(Duration) would end up emitting at 1Hz.

This is closer to delaySubscription(Duration), except the source is subscribed to immediately.

Parameters:

delay - Duration to shift the sequence by

Returns:

an shifted Flux emitting at the same frequency as the source

delaySequence

public final Flux<T> delaySequence(Duration delay,
                                   Scheduler timer)

Shift this Flux forward in time by a given Duration. Unlike with delayElements(Duration, Scheduler), elements are shifted forward in time as they are emitted, always resulting in the delay between two elements being the same as in the source (only the first element is visibly delayed from the previous event, that is the subscription). Signals are delayed and continue on an user-specified Scheduler, but empty sequences or immediate error signals are not delayed.

With this operator, a source emitting at 10Hz with a delaySequence Duration of 1s will still emit at 10Hz, with an initial "hiccup" of 1s. On the other hand, delayElements(Duration, Scheduler) would end up emitting at 1Hz.

This is closer to delaySubscription(Duration, Scheduler), except the source is subscribed to immediately.

Parameters:

delay - Duration to shift the sequence by

timer - a time-capable Scheduler instance to delay signals on

Returns:

an shifted Flux emitting at the same frequency as the source

delayUntil

public final Flux<T> delayUntil(Function<? super T,? extends Publisher<?>> triggerProvider)

Subscribe to this Flux and generate a Publisher from each of this Flux elements, each acting as a trigger for relaying said element.

That is to say, the resulting Flux delays each of its emission until the associated trigger Publisher terminates.

In case of an error either in the source or in a trigger, that error is propagated immediately downstream. Note that unlike with the Mono variant there is no fusion of subsequent calls.

Parameters:

triggerProvider - a Function that maps each element into a Publisher whose termination will trigger relaying the value.

Returns:

this Flux, but with elements delayed until their derived publisher terminates.

delaySubscription

public final Flux<T> delaySubscription(Duration delay)

Delay the subscription to this Flux source until the given period elapses. The delay is introduced through the parallel default Scheduler.

Parameters:

delay - duration before subscribing this Flux

Returns:

a delayed Flux

delaySubscription

public final Flux<T> delaySubscription(Duration delay,
                                       Scheduler timer)

Delay the subscription to this Flux source until the given period elapses, as measured on the user-provided Scheduler.

Parameters:

delay - Duration before subscribing this Flux

timer - a time-capable Scheduler instance to run on

Returns:

a delayed Flux

delaySubscription

public final <U> Flux<T> delaySubscription(Publisher<U> subscriptionDelay)

Delay the subscription to this Flux source until another Publisher signals a value or completes.

Type Parameters:

U - the other source type

Parameters:

subscriptionDelay - a companion Publisher whose onNext/onComplete signal will trigger the subscription

Returns:

a delayed Flux

dematerialize

public final <X> Flux<X> dematerialize()

An operator working only if this Flux emits onNext, onError or onComplete Signal instances, transforming these materialized signals into real signals on the Subscriber. The error Signal will trigger onError and complete Signal will trigger onComplete.

Type Parameters:

X - the dematerialized type

Returns:

a dematerialized Flux

See Also:

materialize()

distinct

public final Flux<T> distinct()

For each Subscriber, track elements from this Flux that have been seen and filter out duplicates.

The values themselves are recorded into a HashSet for distinct detection. Use distinct(Object::hashcode) if you want a more lightweight approach that doesn't retain all the objects, but is more susceptible to falsely considering two elements as distinct due to a hashcode collision.

Returns:

a filtering Flux only emitting distinct values

distinct

public final <V> Flux<T> distinct(Function<? super T,? extends V> keySelector)

For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by a key extracted through the user provided Function.

Type Parameters:

V - the type of the key extracted from each value in this sequence

Parameters:

keySelector - function to compute comparison key for each element

Returns:

a filtering Flux only emitting values with distinct keys

distinct

public final <V,C extends Collection<? super V>> Flux<T> distinct(Function<? super T,? extends V> keySelector,
                                                                  Supplier<C> distinctCollectionSupplier)

For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by a key extracted through the user provided Function and by the add method of the Collection supplied (typically a Set).

Type Parameters:

V - the type of the key extracted from each value in this sequence

C - the type of Collection used for distinct checking of keys

Parameters:

keySelector - function to compute comparison key for each element

distinctCollectionSupplier - supplier of the Collection used for distinct check through add of the key.

Returns:

a filtering Flux only emitting values with distinct keys

distinct

public final <V,C> Flux<T> distinct(Function<? super T,? extends V> keySelector,
                                    Supplier<C> distinctStoreSupplier,
                                    BiPredicate<C,V> distinctPredicate,
                                    Consumer<C> cleanup)

For each Subscriber, track elements from this Flux that have been seen and filter out duplicates, as compared by applying a BiPredicate on an arbitrary user-supplied <C> store and a key extracted through the user provided Function. The BiPredicate should typically add the key to the arbitrary store for further comparison. A cleanup callback is also invoked on the store upon termination of the sequence.

Type Parameters:

V - the type of the key extracted from each value in this sequence

C - the type of store backing the BiPredicate

Parameters:

keySelector - function to compute comparison key for each element

distinctStoreSupplier - supplier of the arbitrary store object used in distinct checks along the extracted key.

distinctPredicate - the BiPredicate to apply to the arbitrary store + extracted key to perform a distinct check. Since nothing is assumed of the store, this predicate should also add the key to the store as necessary.

cleanup - the cleanup callback to invoke on the store upon termination.

Returns:

a filtering Flux only emitting values with distinct keys

distinctUntilChanged

public final Flux<T> distinctUntilChanged()

Filter out subsequent repetitions of an element (that is, if they arrive right after one another).

The values themselves are recorded into a HashSet for distinct detection. Use distinctUntilChanged(Object::hashcode) if you want a more lightweight approach that doesn't retain all the objects, but is more susceptible to falsely considering two elements as distinct due to a hashcode collision.

Returns:

a filtering Flux with only one occurrence in a row of each element (yet elements can repeat in the overall sequence)

distinctUntilChanged

public final <V> Flux<T> distinctUntilChanged(Function<? super T,? extends V> keySelector)

Filter out subsequent repetitions of an element (that is, if they arrive right after one another), as compared by a key extracted through the user provided Function using equality.

Type Parameters:

V - the type of the key extracted from each value in this sequence

Parameters:

keySelector - function to compute comparison key for each element

Returns:

a filtering Flux with only one occurrence in a row of each element of the same key (yet element keys can repeat in the overall sequence)

distinctUntilChanged

public final <V> Flux<T> distinctUntilChanged(Function<? super T,? extends V> keySelector,
                                              BiPredicate<? super V,? super V> keyComparator)

Filter out subsequent repetitions of an element (that is, if they arrive right after one another), as compared by a key extracted through the user provided Function and then comparing keys with the supplied BiPredicate.

Type Parameters:

V - the type of the key extracted from each value in this sequence

Parameters:

keySelector - function to compute comparison key for each element

keyComparator - predicate used to compare keys.

Returns:

a filtering Flux with only one occurrence in a row of each element of the same key for which the predicate returns true (yet element keys can repeat in the overall sequence)

doAfterTerminate

public final Flux<T> doAfterTerminate(Runnable afterTerminate)

Add behavior (side-effect) triggered after the Flux terminates, either by completing downstream successfully or with an error.

Parameters:

afterTerminate - the callback to call after Subscriber.onComplete() or Subscriber.onError(java.lang.Throwable)

Returns:

an observed Flux

doOnCancel

public final Flux<T> doOnCancel(Runnable onCancel)

Add behavior (side-effect) triggered when the Flux is cancelled.

Parameters:

onCancel - the callback to call on Subscription.cancel()

Returns:

an observed Flux

doOnComplete

public final Flux<T> doOnComplete(Runnable onComplete)

Add behavior (side-effect) triggered when the Flux completes successfully.

Parameters:

onComplete - the callback to call on Subscriber.onComplete()

Returns:

an observed Flux

doOnEach

public final Flux<T> doOnEach(Consumer<? super Signal<T>> signalConsumer)

Add behavior (side-effects) triggered when the Flux emits an item, fails with an error or completes successfully. All these events are represented as a Signal that is passed to the side-effect callback. Note that this is an advanced operator, typically used for monitoring of a Flux. These Signal have a Context associated to them.

Parameters:

signalConsumer - the mandatory callback to call on Subscriber.onNext(Object), Subscriber.onError(Throwable) and Subscriber.onComplete()

Returns:

an observed Flux

See Also:

doOnNext(Consumer), doOnError(Consumer), doOnComplete(Runnable), materialize(), Signal

doOnError

public final Flux<T> doOnError(Consumer<? super Throwable> onError)

Add behavior (side-effect) triggered when the Flux completes with an error.

Parameters:

onError - the callback to call on Subscriber.onError(java.lang.Throwable)

Returns:

an observed Flux

doOnError

public final <E extends Throwable> Flux<T> doOnError(Class<E> exceptionType,
                                                     Consumer<? super E> onError)

Add behavior (side-effect) triggered when the Flux completes with an error matching the given exception type.

Type Parameters:

E - type of the error to handle

Parameters:

exceptionType - the type of exceptions to handle

onError - the error handler for each error

Returns:

an observed Flux

doOnError

public final Flux<T> doOnError(Predicate<? super Throwable> predicate,
                               Consumer<? super Throwable> onError)

Add behavior (side-effect) triggered when the Flux completes with an error matching the given exception.

Parameters:

predicate - the matcher for exceptions to handle

onError - the error handler for each error

Returns:

an observed Flux

doOnNext

public final Flux<T> doOnNext(Consumer<? super T> onNext)

Add behavior (side-effect) triggered when the Flux emits an item.

Parameters:

onNext - the callback to call on Subscriber.onNext(T)

Returns:

an observed Flux

doOnRequest

public final Flux<T> doOnRequest(LongConsumer consumer)

Add behavior (side-effect) triggering a LongConsumer when this Flux receives any request.

Note that non fatal error raised in the callback will not be propagated and will simply trigger Operators.onOperatorError(Throwable, Context).

Parameters:

consumer - the consumer to invoke on each request

Returns:

an observed Flux

doOnSubscribe

public final Flux<T> doOnSubscribe(Consumer<? super Subscription> onSubscribe)

Add behavior (side-effect) triggered when the Flux is subscribed.

This method is not intended for capturing the subscription and calling its methods, but for side effects like monitoring. For instance, the correct way to cancel a subscription is to call Disposable.dispose() on the Disposable returned by subscribe().

Parameters:

onSubscribe - the callback to call on Subscriber.onSubscribe(org.reactivestreams.Subscription)

Returns:

an observed Flux

doOnTerminate

public final Flux<T> doOnTerminate(Runnable onTerminate)

Add behavior (side-effect) triggered when the Flux terminates, either by completing successfully or with an error.

Parameters:

onTerminate - the callback to call on Subscriber.onComplete() or Subscriber.onError(java.lang.Throwable)

Returns:

an observed Flux

doFinally

public final Flux<T> doFinally(Consumer<SignalType> onFinally)

Add behavior (side-effect) triggered after the Flux terminates for any reason, including cancellation. The terminating event (SignalType.ON_COMPLETE, SignalType.ON_ERROR and SignalType.CANCEL) is passed to the consumer, which is executed after the signal has been passed downstream.

Note that the fact that the signal is propagated downstream before the callback is executed means that several doFinally in a row will be executed in reverse order. If you want to assert the execution of the callback please keep in mind that the Flux will complete before it is executed, so its effect might not be visible immediately after eg. a blockLast().

Parameters:

onFinally - the callback to execute after a terminal signal (complete, error or cancel)

Returns:

an observed Flux

elapsed

public final Flux<Tuple2<Long,T>> elapsed()

Map this Flux into Tuple2<Long, T> of timemillis and source data. The timemillis corresponds to the elapsed time between each signal as measured by the parallel scheduler. First duration is measured between the subscription and the first element.

Returns:

a new Flux that emits a tuple of time elapsed in milliseconds and matching data

elapsed

public final Flux<Tuple2<Long,T>> elapsed(Scheduler scheduler)

Map this Flux into Tuple2<Long, T> of timemillis and source data. The timemillis corresponds to the elapsed time between each signal as measured by the provided Scheduler. First duration is measured between the subscription and the first element.

Parameters:

scheduler - a Scheduler instance to read time from

Returns:

a new Flux that emits tuples of time elapsed in milliseconds and matching data

elementAt

public final Mono<T> elementAt(int index)

Emit only the element at the given index position or IndexOutOfBoundsException if the sequence is shorter.

Parameters:

index - zero-based index of the only item to emit

Returns:

a Mono of the item at the specified zero-based index

elementAt

public final Mono<T> elementAt(int index,
                               T defaultValue)

Emit only the element at the given index position or fall back to a default value if the sequence is shorter.

Parameters:

index - zero-based index of the only item to emit

defaultValue - a default value to emit if the sequence is shorter

Returns:

a Mono of the item at the specified zero-based index or a default value

expandDeep

public final Flux<T> expandDeep(Function<? super T,? extends Publisher<? extends T>> expander,
                                int capacityHint)

Recursively expand elements into a graph and emit all the resulting element, in a depth-first traversal order.

That is: emit one value from this Flux, expand it and emit the first value at this first level of recursion, and so on... When no more recursion is possible, backtrack to the previous level and re-apply the strategy.

For example, given the hierarchical structure

  A
   - AA
     - aa1
  B
   - BB
     - bb1
 

Expands Flux.just(A, B) into

  A
  AA
  aa1
  B
  BB
  bb1
 

Parameters:

expander - the Function applied at each level of recursion to expand values into a Publisher, producing a graph.

capacityHint - a capacity hint to prepare the inner queues to accommodate n elements per level of recursion.

Returns:

a Flux expanded depth-first

expandDeep

public final Flux<T> expandDeep(Function<? super T,? extends Publisher<? extends T>> expander)

Recursively expand elements into a graph and emit all the resulting element, in a depth-first traversal order.

That is: emit one value from this Flux, expand it and emit the first value at this first level of recursion, and so on... When no more recursion is possible, backtrack to the previous level and re-apply the strategy.

For example, given the hierarchical structure

  A
   - AA
     - aa1
  B
   - BB
     - bb1
 

Expands Flux.just(A, B) into

  A
  AA
  aa1
  B
  BB
  bb1
 

Parameters:

expander - the Function applied at each level of recursion to expand values into a Publisher, producing a graph.

Returns:

a Flux expanded depth-first

expand

public final Flux<T> expand(Function<? super T,? extends Publisher<? extends T>> expander,
                            int capacityHint)

Recursively expand elements into a graph and emit all the resulting element using a breadth-first traversal strategy.

That is: emit the values from this Flux first, then expand each at a first level of recursion and emit all of the resulting values, then expand all of these at a second level and so on..

For example, given the hierarchical structure

  A
   - AA
     - aa1
  B
   - BB
     - bb1
 

Expands Flux.just(A, B) into

  A
  B
  AA
  BB
  aa1
  bb1
 

Parameters:

expander - the Function applied at each level of recursion to expand values into a Publisher, producing a graph.

capacityHint - a capacity hint to prepare the inner queues to accommodate n elements per level of recursion.

Returns:

an breadth-first expanded Flux

expand

public final Flux<T> expand(Function<? super T,? extends Publisher<? extends T>> expander)

Recursively expand elements into a graph and emit all the resulting element using a breadth-first traversal strategy.

That is: emit the values from this Flux first, then expand each at a first level of recursion and emit all of the resulting values, then expand all of these at a second level and so on..

For example, given the hierarchical structure

  A
   - AA
     - aa1
  B
   - BB
     - bb1
 

Expands Flux.just(A, B) into

  A
  B
  AA
  BB
  aa1
  bb1
 

Parameters:

expander - the Function applied at each level of recursion to expand values into a Publisher, producing a graph.

Returns:

an breadth-first expanded Flux

filter

public final Flux<T> filter(Predicate<? super T> p)

Evaluate each source value against the given Predicate. If the predicate test succeeds, the value is emitted. If the predicate test fails, the value is ignored and a request of 1 is made upstream.

Parameters:

p - the Predicate to test values against

Returns:

a new Flux containing only values that pass the predicate test

filterWhen

public final Flux<T> filterWhen(Function<? super T,? extends Publisher<Boolean>> asyncPredicate)

Test each value emitted by this Flux asynchronously using a generated Publisher<Boolean> test. A value is replayed if the first item emitted by its corresponding test is true. It is dropped if its test is either empty or its first emitted value is false.

Note that only the first value of the test publisher is considered, and unless it is a Mono, test will be cancelled after receiving that first value. Test publishers are generated and subscribed to in sequence.

Parameters:

asyncPredicate - the function generating a Publisher of Boolean for each value, to filter the Flux with

Returns:

a filtered Flux

filterWhen

public final Flux<T> filterWhen(Function<? super T,? extends Publisher<Boolean>> asyncPredicate,
                                int bufferSize)

Test each value emitted by this Flux asynchronously using a generated Publisher<Boolean> test. A value is replayed if the first item emitted by its corresponding test is true. It is dropped if its test is either empty or its first emitted value is false.

Note that only the first value of the test publisher is considered, and unless it is a Mono, test will be cancelled after receiving that first value. Test publishers are generated and subscribed to in sequence.

Parameters:

asyncPredicate - the function generating a Publisher of Boolean for each value, to filter the Flux with

bufferSize - the maximum expected number of values to hold pending a result of their respective asynchronous predicates, rounded to the next power of two. This is capped depending on the size of the heap and the JVM limits, so be careful with large values (although eg. 65536 should still be fine). Also serves as the initial request size for the source.

Returns:

a filtered Flux

flatMap

public final <R> Flux<R> flatMap(Function<? super T,? extends Publisher<? extends R>> mapper)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.

There are three dimensions to this operator that can be compared with flatMapSequential and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners.
• Ordering of the flattened values: this operator does not necessarily preserve original ordering, as inner element are flattened as they arrive.
• Interleaving: this operator lets values from different inners interleave (similar to merging the inner sequences).

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

Returns:

a new Flux

flatMap

public final <V> Flux<V> flatMap(Function<? super T,? extends Publisher<? extends V>> mapper,
                                 int concurrency)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.

There are three dimensions to this operator that can be compared with flatMapSequential and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners.
• Ordering of the flattened values: this operator does not necessarily preserve original ordering, as inner element are flattened as they arrive.
• Interleaving: this operator lets values from different inners interleave (similar to merging the inner sequences).

The concurrency argument allows to control how many Publisher can be subscribed to and merged in parallel.

Type Parameters:

V - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

concurrency - the maximum number of in-flight inner sequences

Returns:

a new Flux

flatMap

public final <V> Flux<V> flatMap(Function<? super T,? extends Publisher<? extends V>> mapper,
                                 int concurrency,
                                 int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.

There are three dimensions to this operator that can be compared with flatMapSequential and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners.
• Ordering of the flattened values: this operator does not necessarily preserve original ordering, as inner element are flattened as they arrive.
• Interleaving: this operator lets values from different inners interleave (similar to merging the inner sequences).

The concurrency argument allows to control how many Publisher can be subscribed to and merged in parallel. The prefetch argument allows to give an arbitrary prefetch size to the merged Publisher.

Type Parameters:

V - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

concurrency - the maximum number of in-flight inner sequences

prefetch - the maximum in-flight elements from each inner Publisher sequence

Returns:

a merged Flux

flatMapDelayError

public final <V> Flux<V> flatMapDelayError(Function<? super T,? extends Publisher<? extends V>> mapper,
                                           int concurrency,
                                           int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave.

There are three dimensions to this operator that can be compared with flatMapSequential and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners.
• Ordering of the flattened values: this operator does not necessarily preserve original ordering, as inner element are flattened as they arrive.
• Interleaving: this operator lets values from different inners interleave (similar to merging the inner sequences).

The concurrency argument allows to control how many Publisher can be subscribed to and merged in parallel. The prefetch argument allows to give an arbitrary prefetch size to the merged Publisher. This variant will delay any error until after the rest of the flatMap backlog has been processed.

Type Parameters:

V - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

concurrency - the maximum number of in-flight inner sequences

prefetch - the maximum in-flight elements from each inner Publisher sequence

Returns:

a merged Flux

flatMap

public final <R> Flux<R> flatMap(@Nullable
                                 Function<? super T,? extends Publisher<? extends R>> mapperOnNext,
                                 @Nullable
                                 Function<? super Throwable,? extends Publisher<? extends R>> mapperOnError,
                                 @Nullable
                                 Supplier<? extends Publisher<? extends R>> mapperOnComplete)

Transform the signals emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux through merging, which allow them to interleave. Note that at least one of the signal mappers must be provided, and all provided mappers must produce a publisher.

There are three dimensions to this operator that can be compared with flatMapSequential and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners.
• Ordering of the flattened values: this operator does not necessarily preserve original ordering, as inner element are flattened as they arrive.
• Interleaving: this operator lets values from different inners interleave (similar to merging the inner sequences).

OnError will be transformed into completion signal after its mapping callback has been applied.

Type Parameters:

R - the output Publisher type target

Parameters:

mapperOnNext - the Function to call on next data and returning a sequence to merge. Use null to ignore (provided at least one other mapper is specified).

mapperOnError - the Function to call on error signal and returning a sequence to merge. Use null to ignore (provided at least one other mapper is specified).

mapperOnComplete - the Function to call on complete signal and returning a sequence to merge. Use null to ignore (provided at least one other mapper is specified).

Returns:

a new Flux

flatMapIterable

public final <R> Flux<R> flatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper)

Transform the items emitted by this Flux into Iterable, then flatten the elements from those by merging them into a single Flux.

Note that unlike flatMap(Function) and concatMap(Function), with Iterable there is no notion of eager vs lazy inner subscription. The content of the Iterables are all played sequentially. Thus flatMapIterable and concatMapIterable are equivalent offered as a discoverability improvement for users that explore the API with the concat vs flatMap expectation.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N Iterable

Returns:

a concatenation of the values from the Iterables obtained from each element in this Flux

flatMapIterable

public final <R> Flux<R> flatMapIterable(Function<? super T,? extends Iterable<? extends R>> mapper,
                                         int prefetch)

Transform the items emitted by this Flux into Iterable, then flatten the emissions from those by merging them into a single Flux. The prefetch argument allows to give an arbitrary prefetch size to the merged Iterable.

Note that unlike flatMap(Function) and concatMap(Function), with Iterable there is no notion of eager vs lazy inner subscription. The content of the Iterables are all played sequentially. Thus flatMapIterable and concatMapIterable are equivalent offered as a discoverability improvement for users that explore the API with the concat vs flatMap expectation.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N Iterable

prefetch - the maximum in-flight elements from each inner Iterable sequence

Returns:

a concatenation of the values from the Iterables obtained from each element in this Flux

flatMapSequential

public final <R> Flux<R> flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.

There are three dimensions to this operator that can be compared with flatMap and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners (like flatMap).
• Ordering of the flattened values: this operator queues elements from late inners until all elements from earlier inners have been emitted, thus emitting inner sequences as a whole, in an order that matches their source's order.
• Interleaving: this operator does not let values from different inners interleave (similar looking result to concatMap, but due to queueing of values that would have been interleaved otherwise).

That is to say, whenever a source element is emitted it is transformed to an inner Publisher. However, if such an early inner takes more time to complete than subsequent faster inners, the data from these faster inners will be queued until the earlier inner completes, so as to maintain source ordering.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

Returns:

a merged Flux, subscribing early but keeping the original ordering

flatMapSequential

public final <R> Flux<R> flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper,
                                           int maxConcurrency)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.

There are three dimensions to this operator that can be compared with flatMap and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners (like flatMap).
• Ordering of the flattened values: this operator queues elements from late inners until all elements from earlier inners have been emitted, thus emitting inner sequences as a whole, in an order that matches their source's order.
• Interleaving: this operator does not let values from different inners interleave (similar looking result to concatMap, but due to queueing of values that would have been interleaved otherwise).

That is to say, whenever a source element is emitted it is transformed to an inner Publisher. However, if such an early inner takes more time to complete than subsequent faster inners, the data from these faster inners will be queued until the earlier inner completes, so as to maintain source ordering.

The concurrency argument allows to control how many merged Publisher can happen in parallel.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

maxConcurrency - the maximum number of in-flight inner sequences

Returns:

a merged Flux, subscribing early but keeping the original ordering

flatMapSequential

public final <R> Flux<R> flatMapSequential(Function<? super T,? extends Publisher<? extends R>> mapper,
                                           int maxConcurrency,
                                           int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.

There are three dimensions to this operator that can be compared with flatMap and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners (like flatMap).
• Ordering of the flattened values: this operator queues elements from late inners until all elements from earlier inners have been emitted, thus emitting inner sequences as a whole, in an order that matches their source's order.
• Interleaving: this operator does not let values from different inners interleave (similar looking result to concatMap, but due to queueing of values that would have been interleaved otherwise).

That is to say, whenever a source element is emitted it is transformed to an inner Publisher. However, if such an early inner takes more time to complete than subsequent faster inners, the data from these faster inners will be queued until the earlier inner completes, so as to maintain source ordering.

The concurrency argument allows to control how many merged Publisher can happen in parallel. The prefetch argument allows to give an arbitrary prefetch size to the merged Publisher.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

maxConcurrency - the maximum number of in-flight inner sequences

prefetch - the maximum in-flight elements from each inner Publisher sequence

Returns:

a merged Flux, subscribing early but keeping the original ordering

flatMapSequentialDelayError

public final <R> Flux<R> flatMapSequentialDelayError(Function<? super T,? extends Publisher<? extends R>> mapper,
                                                     int maxConcurrency,
                                                     int prefetch)

Transform the elements emitted by this Flux asynchronously into Publishers, then flatten these inner publishers into a single Flux, but merge them in the order of their source element.

There are three dimensions to this operator that can be compared with flatMap and concatMap:

• Generation of inners and subscription: this operator is eagerly subscribing to its inners (like flatMap).
• Ordering of the flattened values: this operator queues elements from late inners until all elements from earlier inners have been emitted, thus emitting inner sequences as a whole, in an order that matches their source's order.
• Interleaving: this operator does not let values from different inners interleave (similar looking result to concatMap, but due to queueing of values that would have been interleaved otherwise).

That is to say, whenever a source element is emitted it is transformed to an inner Publisher. However, if such an early inner takes more time to complete than subsequent faster inners, the data from these faster inners will be queued until the earlier inner completes, so as to maintain source ordering.

The concurrency argument allows to control how many merged Publisher can happen in parallel. The prefetch argument allows to give an arbitrary prefetch size to the merged Publisher. This variant will delay any error until after the rest of the flatMap backlog has been processed.

Type Parameters:

R - the merged output sequence type

Parameters:

mapper - the Function to transform input sequence into N sequences Publisher

maxConcurrency - the maximum number of in-flight inner sequences

prefetch - the maximum in-flight elements from each inner Publisher sequence

Returns:

a merged Flux, subscribing early but keeping the original ordering

getPrefetch

public int getPrefetch()

The prefetch configuration of the Flux

Returns:

the prefetch configuration of the Flux, -1 if unspecified

groupBy

public final <K> Flux<GroupedFlux<K,T>> groupBy(Function<? super T,? extends K> keyMapper)

Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function. Note that groupBy works best with a low cardinality of groups, so chose your keyMapper function accordingly.

The groups need to be drained and consumed downstream for groupBy to work correctly. Notably when the criteria produces a large amount of groups, it can lead to hanging if the groups are not suitably consumed downstream (eg. due to a flatMap with a maxConcurrency parameter that is set too low).

Type Parameters:

K - the key type extracted from each value of this sequence

Parameters:

keyMapper - the key mapping Function that evaluates an incoming data and returns a key.

Returns:

a Flux of GroupedFlux grouped sequences

groupBy

public final <K> Flux<GroupedFlux<K,T>> groupBy(Function<? super T,? extends K> keyMapper,
                                                int prefetch)

Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function. Note that groupBy works best with a low cardinality of groups, so chose your keyMapper function accordingly.

The groups need to be drained and consumed downstream for groupBy to work correctly. Notably when the criteria produces a large amount of groups, it can lead to hanging if the groups are not suitably consumed downstream (eg. due to a flatMap with a maxConcurrency parameter that is set too low).

Type Parameters:

K - the key type extracted from each value of this sequence

Parameters:

keyMapper - the key mapping Function that evaluates an incoming data and returns a key.

prefetch - the number of values to prefetch from the source

Returns:

a Flux of GroupedFlux grouped sequences

groupBy

public final <K,V> Flux<GroupedFlux<K,V>> groupBy(Function<? super T,? extends K> keyMapper,
                                                  Function<? super T,? extends V> valueMapper)

Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function. Source elements are also mapped to a different value using the valueMapper. Note that groupBy works best with a low cardinality of groups, so chose your keyMapper function accordingly.

The groups need to be drained and consumed downstream for groupBy to work correctly. Notably when the criteria produces a large amount of groups, it can lead to hanging if the groups are not suitably consumed downstream (eg. due to a flatMap with a maxConcurrency parameter that is set too low).

Type Parameters:

K - the key type extracted from each value of this sequence

V - the value type extracted from each value of this sequence

Parameters:

keyMapper - the key mapping function that evaluates an incoming data and returns a key.

valueMapper - the value mapping function that evaluates which data to extract for re-routing.

Returns:

a Flux of GroupedFlux grouped sequences

groupBy

public final <K,V> Flux<GroupedFlux<K,V>> groupBy(Function<? super T,? extends K> keyMapper,
                                                  Function<? super T,? extends V> valueMapper,
                                                  int prefetch)

Divide this sequence into dynamically created Flux (or groups) for each unique key, as produced by the provided keyMapper Function. Source elements are also mapped to a different value using the valueMapper. Note that groupBy works best with a low cardinality of groups, so chose your keyMapper function accordingly.

The groups need to be drained and consumed downstream for groupBy to work correctly. Notably when the criteria produces a large amount of groups, it can lead to hanging if the groups are not suitably consumed downstream (eg. due to a flatMap with a maxConcurrency parameter that is set too low).

Type Parameters:

K - the key type extracted from each value of this sequence

V - the value type extracted from each value of this sequence

Parameters:

keyMapper - the key mapping function that evaluates an incoming data and returns a key.

valueMapper - the value mapping function that evaluates which data to extract for re-routing.

prefetch - the number of values to prefetch from the source

Returns:

a Flux of GroupedFlux grouped sequences

groupJoin

public final <TRight,TLeftEnd,TRightEnd,R> Flux<R> groupJoin(Publisher<? extends TRight> other,
                                                             Function<? super T,? extends Publisher<TLeftEnd>> leftEnd,
                                                             Function<? super TRight,? extends Publisher<TRightEnd>> rightEnd,
                                                             BiFunction<? super T,? super Flux<TRight>,? extends R> resultSelector)

Map values from two Publishers into time windows and emit combination of values in case their windows overlap. The emitted elements are obtained by passing the value from this Flux and a Flux emitting the value from the other Publisher to a BiFunction.

There are no guarantees in what order the items get combined when multiple items from one or both source Publishers overlap.

Unlike join(org.reactivestreams.Publisher<? extends TRight>, java.util.function.Function<? super T, ? extends org.reactivestreams.Publisher<TLeftEnd>>, java.util.function.Function<? super TRight, ? extends org.reactivestreams.Publisher<TRightEnd>>, java.util.function.BiFunction<? super T, ? super TRight, ? extends R>), items from the second Publisher will be provided as a Flux to the resultSelector.

Type Parameters:

TRight - the type of the elements from the right Publisher

TLeftEnd - the type for this Flux window signals

TRightEnd - the type for the right Publisher window signals

R - the combined result type

Parameters:

other - the other Publisher to correlate items with

leftEnd - a function that returns a Publisher whose emissions indicate the time window for the source value to be considered

rightEnd - a function that returns a Publisher whose emissions indicate the time window for the right Publisher value to be considered

resultSelector - a function that takes an item emitted by this Flux and a Flux representation of the overlapping item from the other Publisher and returns the value to be emitted by the resulting Flux

Returns:

a joining Flux

See Also:

join(Publisher, Function, Function, BiFunction)

handle

public final <R> Flux<R> handle(BiConsumer<? super T,SynchronousSink<R>> handler)

Handle the items emitted by this Flux by calling a biconsumer with the output sink for each onNext. At most one SynchronousSink.next(Object) call must be performed and/or 0 or 1 SynchronousSink.error(Throwable) or SynchronousSink.complete().

Type Parameters:

R - the transformed type

Parameters:

handler - the handling BiConsumer

Returns:

a transformed Flux

hasElement

public final Mono<Boolean> hasElement(T value)

Emit a single boolean true if any of the elements of this Flux sequence is equal to the provided value.

The implementation uses short-circuit logic and completes with true if an element matches the value.

Parameters:

value - constant compared to incoming signals

Returns:

a new Flux with true if any element is equal to a given value and false otherwise

hasElements

public final Mono<Boolean> hasElements()

Emit a single boolean true if this Flux sequence has at least one element.

The implementation uses short-circuit logic and completes with true on onNext.

Returns:

a new Mono with true if any value is emitted and false otherwise

hide

public final Flux<T> hide()

Hides the identities of this Flux instance.

The main purpose of this operator is to prevent certain identity-based optimizations from happening, mostly for diagnostic purposes.

Returns:

a new Flux preventing Publisher / Subscription based Reactor optimizations

index

public final Flux<Tuple2<Long,T>> index()

Keep information about the order in which source values were received by indexing them with a 0-based incrementing long, returning a Flux of Tuple2<(index, value)>.

Returns:

an indexed Flux with each source value combined with its 0-based index.

index

public final <I> Flux<I> index(BiFunction<? super Long,? super T,? extends I> indexMapper)

Keep information about the order in which source values were received by indexing them internally with a 0-based incrementing long then combining this information with the source value into a I using the provided BiFunction, returning a Flux<I>.

Typical usage would be to produce a Tuple2 similar to index(), but 1-based instead of 0-based:

index((i, v) -> Tuples.of(i+1, v))

Parameters:

indexMapper - the BiFunction to use to combine elements and their index.

Returns:

an indexed Flux with each source value combined with its computed index.

ignoreElements

public final Mono<T> ignoreElements()

Ignores onNext signals (dropping them) and only propagate termination events.

Returns:

a new empty Mono representing the completion of this Flux.

join

public final <TRight,TLeftEnd,TRightEnd,R> Flux<R> join(Publisher<? extends TRight> other,
                                                        Function<? super T,? extends Publisher<TLeftEnd>> leftEnd,
                                                        Function<? super TRight,? extends Publisher<TRightEnd>> rightEnd,
                                                        BiFunction<? super T,? super TRight,? extends R> resultSelector)

Map values from two Publishers into time windows and emit combination of values in case their windows overlap. The emitted elements are obtained by passing the values from this Flux and the other Publisher to a BiFunction.

There are no guarantees in what order the items get combined when multiple items from one or both source Publishers overlap.

Type Parameters:

TRight - the type of the elements from the right Publisher

TLeftEnd - the type for this Flux window signals

TRightEnd - the type for the right Publisher window signals

R - the combined result type

Parameters:

other - the other Publisher to correlate items with

leftEnd - a function that returns a Publisher whose emissions indicate the time window for the source value to be considered

rightEnd - a function that returns a Publisher whose emissions indicate the time window for the right Publisher value to be considered

resultSelector - a function that takes an item emitted by each Publisher and returns the value to be emitted by the resulting Flux

Returns:

a joining Flux

See Also:

groupJoin(Publisher, Function, Function, BiFunction)

last

public final Mono<T> last()

Emit the last element observed before complete signal as a Mono, or emit NoSuchElementException error if the source was empty. For a passive version use takeLast(int)

Returns:

a Mono with the last value in this Flux

last

public final Mono<T> last(T defaultValue)

Emit the last element observed before complete signal as a Mono, or emit the defaultValue if the source was empty. For a passive version use takeLast(int)

Parameters:

defaultValue - a single fallback item if this Flux is empty

Returns:

a Mono with the last value in this Flux

limitRate

public final Flux<T> limitRate(int prefetchRate)

Ensure that backpressure signals from downstream subscribers are split into batches capped at the provided prefetchRate when propagated upstream, effectively rate limiting the upstream Publisher.

Typically used for scenarios where consumer(s) request a large amount of data (eg. Long.MAX_VALUE) but the data source behaves better or can be optimized with smaller requests (eg. database paging, etc...). All data is still processed, unlike with limitRequest(long) which will cap the grand total request amount.

Equivalent to flux.publishOn(Schedulers.immediate(), prefetchRate).subscribe()

Parameters:

prefetchRate - the limit to apply to downstream's backpressure

Returns:

a Flux limiting downstream's backpressure

See Also:

publishOn(Scheduler, int), limitRequest(long)

limitRate

public final Flux<T> limitRate(int highTide,
                               int lowTide)

Ensure that backpressure signals from downstream subscribers are split into batches capped at the provided highTide first, then replenishing at the provided lowTide, effectively rate limiting the upstream Publisher.

Typically used for scenarios where consumer(s) request a large amount of data (eg. Long.MAX_VALUE) but the data source behaves better or can be optimized with smaller requests (eg. database paging, etc...). All data is still processed, unlike with limitRequest(long) which will cap the grand total request amount.

Similar to flux.publishOn(Schedulers.immediate(), prefetchRate).subscribe() , except with a customized "low tide" instead of the default 75%. Note that the smaller the lowTide is, the higher the potential for concurrency between request and data production. And thus the more extraneous replenishment requests this operator could make. For example, for a global downstream request of 14, with a highTide of 10 and a lowTide of 2, the operator would perform 7 low tide requests, whereas with the default lowTide of 8 it would only perform one.

Parameters:

highTide - the initial request amount

lowTide - the subsequent (or replenishing) request amount

Returns:

a Flux limiting downstream's backpressure and customizing the replenishment request amount

See Also:

publishOn(Scheduler, int), limitRequest(long)

limitRequest

public final Flux<T> limitRequest(long requestCap)

Ensure that the total amount requested upstream is capped at cap. Backpressure signals from downstream subscribers are smaller than the cap are propagated as is, but if they would cause the total requested amount to go over the cap, they are reduced to the minimum value that doesn't go over.

As a result, this operator never let the upstream produce more elements than the cap, and it can be used as a stricter form of take(long). Typically useful for cases where a race between request and cancellation can lead the upstream to producing a lot of extraneous data, and such a production is undesirable (e.g. a source that would send the extraneous data over the network).

Parameters:

requestCap - the global backpressure limit to apply to the sum of downstream's requests

Returns:

a Flux that requests AT MOST cap from upstream in total.

See Also:

limitRate(int), take(long)

log

public final Flux<T> log()

Observe all Reactive Streams signals and trace them using Logger support. Default will use Level.INFO and java.util.logging. If SLF4J is available, it will be used instead.

The default log category will be "reactor.Flux.", followed by a suffix generated from the source operator, e.g. "reactor.Flux.Map".

Returns:

a new Flux that logs signals

log

public final Flux<T> log(String category)

Observe all Reactive Streams signals and trace them using Logger support. Default will use Level.INFO and java.util.logging. If SLF4J is available, it will be used instead.

Parameters:

category - to be mapped into logger configuration (e.g. org.springframework .reactor). If category ends with "." like "reactor.", a generated operator suffix will be added, e.g. "reactor.Flux.Map".

Returns:

a new Flux that logs signals

log

public final Flux<T> log(@Nullable
                         String category,
                         Level level,
                         SignalType... options)

Observe Reactive Streams signals matching the passed filter options and trace them using Logger support. Default will use Level.INFO and java.util.logging. If SLF4J is available, it will be used instead.

Options allow fine grained filtering of the traced signal, for instance to only capture onNext and onError:

     flux.log("category", Level.INFO, SignalType.ON_NEXT, SignalType.ON_ERROR)
 

 
 

Parameters:

category - to be mapped into logger configuration (e.g. org.springframework .reactor). If category ends with "." like "reactor.", a generated operator suffix will be added, e.g. "reactor.Flux.Map".

level - the Level to enforce for this tracing Flux (only FINEST, FINE, INFO, WARNING and SEVERE are taken into account)

options - a vararg SignalType option to filter log messages

Returns:

a new Flux that logs signals

log

public final Flux<T> log(@Nullable
                         String category,
                         Level level,
                         boolean showOperatorLine,
                         SignalType... options)

Observe Reactive Streams signals matching the passed filter options and trace them using Logger support. Default will use Level.INFO and java.util.logging. If SLF4J is available, it will be used instead.

Options allow fine grained filtering of the traced signal, for instance to only capture onNext and onError:

     flux.log("category", Level.INFO, SignalType.ON_NEXT, SignalType.ON_ERROR)

 

Parameters:

category - to be mapped into logger configuration (e.g. org.springframework .reactor). If category ends with "." like "reactor.", a generated operator suffix will be added, e.g. "reactor.Flux.Map".

level - the Level to enforce for this tracing Flux (only FINEST, FINE, INFO, WARNING and SEVERE are taken into account)

showOperatorLine - capture the current stack to display operator class/line number.

options - a vararg SignalType option to filter log messages

Returns:

a new Flux that logs signals

log

public final Flux<T> log(Logger logger)

Observe Reactive Streams signals matching the passed filter options and trace them using a specific user-provided Logger, at Level.INFO level.

Parameters:

logger - the Logger to use, instead of resolving one through a category.

Returns:

a new Flux that logs signals

log

public final Flux<T> log(Logger logger,
                         Level level,
                         boolean showOperatorLine,
                         SignalType... options)

Observe Reactive Streams signals matching the passed filter options and trace them using a specific user-provided Logger, at the given Level.

Options allow fine grained filtering of the traced signal, for instance to only capture onNext and onError:

     flux.log(myCustomLogger, Level.INFO, SignalType.ON_NEXT, SignalType.ON_ERROR)

 

Parameters:

logger - the Logger to use, instead of resolving one through a category.

level - the Level to enforce for this tracing Flux (only FINEST, FINE, INFO, WARNING and SEVERE are taken into account)

showOperatorLine - capture the current stack to display operator class/line number (default in overload is false).

options - a vararg SignalType option to filter log messages

Returns:

a new Flux that logs signals

map

public final <V> Flux<V> map(Function<? super T,? extends V> mapper)

Transform the items emitted by this Flux by applying a synchronous function to each item.

Type Parameters:

V - the transformed type

Parameters:

mapper - the synchronous transforming Function

Returns:

a transformed Flux

materialize

public final Flux<Signal<T>> materialize()

Transform incoming onNext, onError and onComplete signals into Signal instances, materializing these signals. Since the error is materialized as a Signal, the propagation will be stopped and onComplete will be emitted. Complete signal will first emit a Signal.complete() and then effectively complete the flux. All these Signal have a Context associated to them.

Returns:

a Flux of materialized Signal

See Also:

dematerialize()

mergeOrderedWith

public final Flux<T> mergeOrderedWith(Publisher<? extends T> other,
                                      Comparator<? super T> otherComparator)

Merge data from this Flux and a Publisher into a reordered merge sequence, by picking the smallest value from each sequence as defined by a provided Comparator. Note that subsequent calls are combined, and their comparators are in lexicographic order as defined by Comparator.thenComparing(Comparator).

The combination step is avoided if the two Comparators are equal (which can easily be achieved by using the same reference, and is also always true of Comparator.naturalOrder()).

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Parameters:

other - the Publisher to merge with

otherComparator - the Comparator to use for merging

Returns:

a new Flux

mergeWith

public final Flux<T> mergeWith(Publisher<? extends T> other)

Merge data from this Flux and a Publisher into an interleaved merged sequence. Unlike concat, inner sources are subscribed to eagerly.

Note that merge is tailored to work with asynchronous sources or finite sources. When dealing with an infinite source that doesn't already publish on a dedicated Scheduler, you must isolate that source in its own Scheduler, as merge would otherwise attempt to drain it before subscribing to another source.

Parameters:

other - the Publisher to merge with

Returns:

a new Flux

name

public final Flux<T> name(String name)

Give a name to this sequence, which can be retrieved using Scannable.name() as long as this is the first reachable Scannable.parents().

Parameters:

name - a name for the sequence

Returns:

the same sequence, but bearing a name

next

public final Mono<T> next()

Emit only the first item emitted by this Flux, into a new Mono.

Returns:

a new Mono emitting the first value in this Flux

ofType

public final <U> Flux<U> ofType(Class<U> clazz)

Evaluate each accepted value against the given Class type. If the a value matches the type, it is passed into the resulting Flux. Otherwise the value is ignored and a request of 1 is emitted.

Parameters:

clazz - the Class type to test values against

Returns:

a new Flux filtered on items of the requested type

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer()

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream. Errors will be delayed until the buffer gets consumed.

Returns:

a backpressured Flux that buffers with unbounded capacity

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(int maxSize)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream. Errors will be immediately emitted on overflow regardless of the pending buffer.

Parameters:

maxSize - maximum buffer backlog size before immediate error

Returns:

a backpressured Flux that buffers with bounded capacity

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(int maxSize,
                                          Consumer<? super T> onOverflow)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream. Overflow error will be delayed after the current backlog is consumed. However the Consumer will be immediately invoked.

Parameters:

maxSize - maximum buffer backlog size before overflow callback is called

onOverflow - callback to invoke on overflow

Returns:

a backpressured Flux that buffers with a bounded capacity

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(int maxSize,
                                          BufferOverflowStrategy bufferOverflowStrategy)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit. Over that limit, the overflow strategy is applied (see BufferOverflowStrategy).

Note that for the ERROR strategy, the overflow error will be delayed after the current backlog is consumed.

Parameters:

maxSize - maximum buffer backlog size before overflow strategy is applied

bufferOverflowStrategy - strategy to apply to overflowing elements

Returns:

a backpressured Flux that buffers up to a capacity then applies an overflow strategy

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(int maxSize,
                                          Consumer<? super T> onBufferOverflow,
                                          BufferOverflowStrategy bufferOverflowStrategy)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit. Over that limit, the overflow strategy is applied (see BufferOverflowStrategy).

A Consumer is immediately invoked when there is an overflow, receiving the value that was discarded because of the overflow (which can be different from the latest element emitted by the source in case of a DROP_LATEST strategy).

Note that for the ERROR strategy, the overflow error will be delayed after the current backlog is consumed. The consumer is still invoked immediately.

Parameters:

maxSize - maximum buffer backlog size before overflow callback is called

onBufferOverflow - callback to invoke on overflow

bufferOverflowStrategy - strategy to apply to overflowing elements

Returns:

a backpressured Flux that buffers up to a capacity then applies an overflow strategy

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(Duration ttl,
                                          int maxSize,
                                          Consumer<? super T> onBufferEviction)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit and for a maximum Duration of ttl (as measured on the elastic Scheduler). Over that limit, oldest elements from the source are dropped.

Elements evicted based on the TTL are passed to a cleanup Consumer, which is also immediately invoked when there is an overflow.

Parameters:

ttl - maximum Duration for which an element is kept in the backlog

maxSize - maximum buffer backlog size before overflow callback is called

onBufferEviction - callback to invoke once TTL is reached or on overflow

Returns:

a backpressured Flux that buffers with a TTL and up to a capacity then applies an overflow strategy

onBackpressureBuffer

public final Flux<T> onBackpressureBuffer(Duration ttl,
                                          int maxSize,
                                          Consumer<? super T> onBufferEviction,
                                          Scheduler scheduler)

Request an unbounded demand and push to the returned Flux, or park the observed elements if not enough demand is requested downstream, within a maxSize limit and for a maximum Duration of ttl (as measured on the provided Scheduler). Over that limit, oldest elements from the source are dropped.

Elements evicted based on the TTL are passed to a cleanup Consumer, which is also immediately invoked when there is an overflow.

Parameters:

ttl - maximum Duration for which an element is kept in the backlog

maxSize - maximum buffer backlog size before overflow callback is called

onBufferEviction - callback to invoke once TTL is reached or on overflow

scheduler - the scheduler on which to run the timeout check

Returns:

a backpressured Flux that buffers with a TTL and up to a capacity then applies an overflow strategy

onBackpressureDrop

public final Flux<T> onBackpressureDrop()

Request an unbounded demand and push to the returned Flux, or drop the observed elements if not enough demand is requested downstream.

Returns:

a backpressured Flux that drops overflowing elements

onBackpressureDrop

public final Flux<T> onBackpressureDrop(Consumer<? super T> onDropped)

Request an unbounded demand and push to the returned Flux, or drop and notify dropping Consumer with the observed elements if not enough demand is requested downstream.

Parameters:

onDropped - the Consumer called when an value gets dropped due to lack of downstream requests

Returns:

a backpressured Flux that drops overflowing elements

onBackpressureError

public final Flux<T> onBackpressureError()

Request an unbounded demand and push to the returned Flux, or emit onError fom Exceptions.failWithOverflow() if not enough demand is requested downstream.

Returns:

a backpressured Flux that errors on overflowing elements

onBackpressureLatest

public final Flux<T> onBackpressureLatest()

Request an unbounded demand and push to the returned Flux, or only keep the most recent observed item if not enough demand is requested downstream.

Returns:

a backpressured Flux that will only keep a reference to the last observed item

onErrorMap

public final Flux<T> onErrorMap(Function<? super Throwable,? extends Throwable> mapper)

Transform any error emitted by this Flux by synchronously applying a function to it.

Parameters:

mapper - the error transforming Function

Returns:

a Flux that transforms source errors to other errors

onErrorMap

public final <E extends Throwable> Flux<T> onErrorMap(Class<E> type,
                                                      Function<? super E,? extends Throwable> mapper)

Transform an error emitted by this Flux by synchronously applying a function to it if the error matches the given type. Otherwise let the error pass through.

Type Parameters:

E - the error type

Parameters:

type - the class of the exception type to react to

mapper - the error transforming Function

Returns:

a Flux that transforms some source errors to other errors

onErrorMap

public final Flux<T> onErrorMap(Predicate<? super Throwable> predicate,
                                Function<? super Throwable,? extends Throwable> mapper)

Transform an error emitted by this Flux by synchronously applying a function to it if the error matches the given predicate. Otherwise let the error pass through.

Parameters:

predicate - the error predicate

mapper - the error transforming Function

Returns:

a Flux that transforms some source errors to other errors

onErrorResume

public final Flux<T> onErrorResume(Function<? super Throwable,? extends Publisher<? extends T>> fallback)

Subscribe to a returned fallback publisher when any error occurs, using a function to choose the fallback depending on the error.

Parameters:

fallback - the function to choose the fallback to an alternative Publisher

Returns:

a Flux falling back upon source onError

onErrorResume

public final <E extends Throwable> Flux<T> onErrorResume(Class<E> type,
                                                         Function<? super E,? extends Publisher<? extends T>> fallback)

Subscribe to a fallback publisher when an error matching the given type occurs, using a function to choose the fallback depending on the error.

Type Parameters:

E - the error type

Parameters:

type - the error type to match

fallback - the function to choose the fallback to an alternative Publisher

Returns:

a Flux falling back upon source onError

onErrorResume

public final Flux<T> onErrorResume(Predicate<? super Throwable> predicate,
                                   Function<? super Throwable,? extends Publisher<? extends T>> fallback)

Subscribe to a fallback publisher when an error matching a given predicate occurs.

Parameters:

predicate - the error predicate to match

fallback - the function to choose the fallback to an alternative Publisher

Returns:

a Flux falling back upon source onError

onErrorReturn

public final Flux<T> onErrorReturn(T fallbackValue)

Simply emit a captured fallback value when any error is observed on this Flux.

Parameters:

fallbackValue - the value to emit if an error occurs

Returns:

a new falling back Flux

onErrorReturn

public final <E extends Throwable> Flux<T> onErrorReturn(Class<E> type,
                                                         T fallbackValue)

Simply emit a captured fallback value when an error of the specified type is observed on this Flux.

Type Parameters:

E - the error type

Parameters:

type - the error type to match

fallbackValue - the value to emit if an error occurs that matches the type

Returns:

a new falling back Flux

onErrorReturn

public final Flux<T> onErrorReturn(Predicate<? super Throwable> predicate,
                                   T fallbackValue)

Simply emit a captured fallback value when an error matching the given predicate is observed on this Flux.

Parameters:

predicate - the error predicate to match

fallbackValue - the value to emit if an error occurs that matches the predicate

Returns:

a new falling back Flux

onTerminateDetach

public final Flux<T> onTerminateDetach()

Detaches both the child Subscriber and the Subscription on termination or cancellation.

This is an advanced interoperability operator that should help with odd retention scenarios when running with non-reactor Subscriber.

Returns:

a detachable Flux

or

public final Flux<T> or(Publisher<? extends T> other)

Pick the first Publisher between this Flux and another publisher to emit any signal (onNext/onError/onComplete) and replay all signals from that Publisher, effectively behaving like the fastest of these competing sources.

Parameters:

other - the Publisher to race with

Returns:

the fastest sequence

See Also:

first(org.reactivestreams.Publisher<? extends I>...)

parallel

public final ParallelFlux<T> parallel()

Prepare this Flux by dividing data on a number of 'rails' matching the number of CPU cores, in a round-robin fashion. Note that to actually perform the work in parallel, you should call ParallelFlux.runOn(Scheduler) afterward.

Returns:

a new ParallelFlux instance

parallel

public final ParallelFlux<T> parallel(int parallelism)

Prepare this Flux by dividing data on a number of 'rails' matching the provided parallelism parameter, in a round-robin fashion. Note that to actually perform the work in parallel, you should call ParallelFlux.runOn(Scheduler) afterward.

Parameters:

parallelism - the number of parallel rails

Returns:

a new ParallelFlux instance

parallel

public final ParallelFlux<T> parallel(int parallelism,
                                      int prefetch)

Prepare this Flux by dividing data on a number of 'rails' matching the provided parallelism parameter, in a round-robin fashion and using a custom prefetch amount and queue for dealing with the source Flux's values. Note that to actually perform the work in parallel, you should call ParallelFlux.runOn(Scheduler) afterward.

Parameters:

parallelism - the number of parallel rails

prefetch - the number of values to prefetch from the source

Returns:

a new ParallelFlux instance

publish

public final ConnectableFlux<T> publish()

Prepare a ConnectableFlux which shares this Flux sequence and dispatches values to subscribers in a backpressure-aware manner. Prefetch will default to Queues.SMALL_BUFFER_SIZE. This will effectively turn any type of sequence into a hot sequence.

Backpressure will be coordinated on Subscription.request(long) and if any Subscriber is missing demand (requested = 0), multicast will pause pushing/pulling.

Returns:

a new ConnectableFlux

publish

public final ConnectableFlux<T> publish(int prefetch)

Prepare a ConnectableFlux which shares this Flux sequence and dispatches values to subscribers in a backpressure-aware manner. This will effectively turn any type of sequence into a hot sequence.

Backpressure will be coordinated on Subscription.request(long) and if any Subscriber is missing demand (requested = 0), multicast will pause pushing/pulling.

Parameters:

prefetch - bounded requested demand

Returns:

a new ConnectableFlux

publish

public final <R> Flux<R> publish(Function<? super Flux<T>,? extends Publisher<? extends R>> transform)

Shares a sequence for the duration of a function that may transform it and consume it as many times as necessary without causing multiple subscriptions to the upstream.

Type Parameters:

R - the output value type

Parameters:

transform - the transformation function

Returns:

a new Flux

publish

public final <R> Flux<R> publish(Function<? super Flux<T>,? extends Publisher<? extends R>> transform,
                                 int prefetch)

Shares a sequence for the duration of a function that may transform it and consume it as many times as necessary without causing multiple subscriptions to the upstream.

Type Parameters:

R - the output value type

Parameters:

transform - the transformation function

prefetch - the request size

Returns:

a new Flux

publishNext

public final Mono<T> publishNext()

Prepare a Mono which shares this Flux sequence and dispatches the first observed item to subscribers in a backpressure-aware manner. This will effectively turn any type of sequence into a hot sequence when the first Subscriber subscribes.

Returns:

a new Mono

publishOn

public final Flux<T> publishOn(Scheduler scheduler)

Run onNext, onComplete and onError on a supplied Scheduler Worker.

This operator influences the threading context where the rest of the operators in the chain below it will execute, up to a new occurrence of publishOn.

Typically used for fast publisher, slow consumer(s) scenarios.

  flux.publishOn(Schedulers.single()).subscribe() 
 

Parameters:

scheduler - a Scheduler providing the Scheduler.Worker where to publish

Returns:

a Flux producing asynchronously on a given Scheduler

publishOn

public final Flux<T> publishOn(Scheduler scheduler,
                               int prefetch)

Run onNext, onComplete and onError on a supplied Scheduler Scheduler.Worker.

This operator influences the threading context where the rest of the operators in the chain below it will execute, up to a new occurrence of publishOn.

Typically used for fast publisher, slow consumer(s) scenarios.

  flux.publishOn(Schedulers.single()).subscribe() 
 

Parameters:

scheduler - a Scheduler providing the Scheduler.Worker where to publish

prefetch - the asynchronous boundary capacity

Returns:

a Flux producing asynchronously

publishOn

public final Flux<T> publishOn(Scheduler scheduler,
                               boolean delayError,
                               int prefetch)

Run onNext, onComplete and onError on a supplied Scheduler Scheduler.Worker.

This operator influences the threading context where the rest of the operators in the chain below it will execute, up to a new occurrence of publishOn.

Typically used for fast publisher, slow consumer(s) scenarios.

  flux.publishOn(Schedulers.single()).subscribe() 
 

Parameters:

scheduler - a Scheduler providing the Scheduler.Worker where to publish

delayError - should the buffer be consumed before forwarding any error

prefetch - the asynchronous boundary capacity

Returns:

a Flux producing asynchronously

reduce

public final Mono<T> reduce(BiFunction<T,T,T> aggregator)

Reduce the values from this Flux sequence into an single object of the same type than the emitted items. Reduction is performed using a BiFunction that takes the intermediate result of the reduction and the current value and returns the next intermediate value of the reduction. It will ignore sequence with 0 or 1 elements.

Parameters:

aggregator - the reducing BiFunction

Returns:

a reduced Flux

reduce

public final <A> Mono<A> reduce(A initial,
                                BiFunction<A,? super T,A> accumulator)

Reduce the values from this Flux sequence into an single object matching the type of a seed value. Reduction is performed using a BiFunction that takes the intermediate result of the reduction and the current value and returns the next intermediate value of the reduction. First element is paired with the seed value, initial.

Type Parameters:

A - the type of the seed and the reduced object

Parameters:

accumulator - the reducing BiFunction

initial - the seed, the initial leftmost argument to pass to the reducing BiFunction

Returns:

a reduced Flux

reduceWith

public final <A> Mono<A> reduceWith(Supplier<A> initial,
                                    BiFunction<A,? super T,A> accumulator)

Reduce the values from this Flux sequence into an single object matching the type of a lazily supplied seed value. Reduction is performed using a BiFunction that takes the intermediate result of the reduction and the current value and returns the next intermediate value of the reduction. First element is paired with the seed value, supplied via initial.

Type Parameters:

A - the type of the seed and the reduced object

Parameters:

accumulator - the reducing BiFunction

initial - a Supplier of the seed, called on subscription and passed to the the reducing BiFunction

Returns:

a reduced Flux

repeat

public final Flux<T> repeat()

Repeatedly and indefinitely subscribe to the source upon completion of the previous subscription.

Returns:

an indefinitely repeated Flux on onComplete

repeat

public final Flux<T> repeat(BooleanSupplier predicate)

Repeatedly subscribe to the source if the predicate returns true after completion of the previous subscription.

Parameters:

predicate - the boolean to evaluate on onComplete.

Returns:

a Flux that repeats on onComplete while the predicate matches

repeat

public final Flux<T> repeat(long numRepeat)

Repeatedly subscribe to the source numRepeat times.

Parameters:

numRepeat - the number of times to re-subscribe on onComplete

Returns:

a Flux that repeats on onComplete, up to the specified number of repetitions

repeat

public final Flux<T> repeat(long numRepeat,
                            BooleanSupplier predicate)

Repeatedly subscribe to the source if the predicate returns true after completion of the previous subscription. A specified maximum of repeat will limit the number of re-subscribe.

Parameters:

numRepeat - the number of times to re-subscribe on complete

predicate - the boolean to evaluate on onComplete

Returns:

a Flux that repeats on onComplete while the predicate matches, up to the specified number of repetitions

repeatWhen

public final Flux<T> repeatWhen(Function<Flux<Long>,? extends Publisher<?>> repeatFactory)

Repeatedly subscribe to this Flux when a companion sequence emits elements in response to the flux completion signal. Any terminal signal from the companion sequence will terminate the resulting Flux with the same signal immediately.

If the companion sequence signals when this Flux is active, the repeat attempt is suppressed.

Note that if the companion Publisher created by the repeatFactory emits Context as trigger objects, these Context will REPLACE the operator's own Context. Please be careful there: replacing the Context means that some keys you don't own could be removed, breaking libraries that depend on them. As a result, the recommended approach is to always create such a Context trigger by starting from the original Context (ensuring the trigger contains all the keys from the original, unless you absolutely know you want to remove one of these keys):

 .repeatWhen(emittedEachAttempt -> emittedEachAttempt
     .flatMap(e -> Mono.subscriberContext().map(ctx -> Tuples.of(e, ctx)))
     .flatMap(t2 -> {
            long lastEmitted = t2.getT1();
            Context ctx = t2.getT2();
            int rl = ctx.getOrDefault("repeatsLeft", 0);
            if (rl > 0) {
                    // /!\ THE ctx.put HERE IS THE ESSENTIAL PART /!\
                    return Mono.just(ctx.put("repeatsLeft", rl - 1)
                                    .put("emitted", lastEmitted));
            } else {
                    return Mono.error(new IllegalStateException("repeats exhausted"));
            }
     })
 )
 

Parameters:

repeatFactory - the Function that returns the associated Publisher companion, given a Flux that signals each onComplete as a Long representing the number of source elements emitted in the latest attempt.

Returns:

a Flux that repeats on onComplete when the companion Publisher produces an onNext signal

replay

public final ConnectableFlux<T> replay()

Turn this Flux into a hot source and cache last emitted signals for further Subscriber. Will retain an unbounded amount of onNext signals. Completion and Error will also be replayed.

Returns:

a replaying ConnectableFlux

replay

public final ConnectableFlux<T> replay(int history)

Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber. Will retain up to the given history size onNext signals. Completion and Error will also be replayed.

Note that cache(0) will only cache the terminal signal without expiration.

Parameters:

history - number of events retained in history excluding complete and error

Returns:

a replaying ConnectableFlux

replay

public final ConnectableFlux<T> replay(Duration ttl)

Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber. Will retain each onNext up to the given per-item expiry timeout.

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription

Parameters:

ttl - Per-item and post termination timeout duration

Returns:

a replaying ConnectableFlux

replay

public final ConnectableFlux<T> replay(int history,
                                       Duration ttl)

Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber. Will retain up to the given history size onNext signals with a per-item ttl.

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription

Parameters:

history - number of events retained in history excluding complete and error

ttl - Per-item and post termination timeout duration

Returns:

a replaying ConnectableFlux

replay

public final ConnectableFlux<T> replay(Duration ttl,
                                       Scheduler timer)

Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber. Will retain onNext signal for up to the given Duration with a per-item ttl.

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription

Parameters:

ttl - Per-item and post termination timeout duration

timer - a time-capable Scheduler instance to read current time from

Returns:

a replaying ConnectableFlux

replay

public final ConnectableFlux<T> replay(int history,
                                       Duration ttl,
                                       Scheduler timer)

Turn this Flux into a connectable hot source and cache last emitted signals for further Subscriber. Will retain up to the given history size onNext signals with a per-item ttl.

Completion and Error will also be replayed until ttl triggers in which case the next Subscriber will start over a new subscription

Parameters:

history - number of events retained in history excluding complete and error

ttl - Per-item and post termination timeout duration

timer - a Scheduler instance to read current time from

Returns:

a replaying ConnectableFlux

retry

public final Flux<T> retry()

Re-subscribes to this Flux sequence if it signals any error, indefinitely.

Returns:

a Flux that retries on onError

retry

public final Flux<T> retry(long numRetries)

Re-subscribes to this Flux sequence if it signals any error, for a fixed number of times.

Note that passing Long.MAX_VALUE is treated as infinite retry.

Parameters:

numRetries - the number of times to tolerate an error

Returns:

a Flux that retries on onError up to the specified number of retry attempts.

retry

public final Flux<T> retry(Predicate<? super Throwable> retryMatcher)

Re-subscribes to this Flux sequence if it signals any error that matches the given Predicate, otherwise push the error downstream.

Parameters:

retryMatcher - the predicate to evaluate if retry should occur based on a given error signal

Returns:

a Flux that retries on onError if the predicates matches.

retry

public final Flux<T> retry(long numRetries,
                           Predicate<? super Throwable> retryMatcher)

Re-subscribes to this Flux sequence up to the specified number of retries if it signals any error that match the given Predicate, otherwise push the error downstream.

Parameters:

numRetries - the number of times to tolerate an error

retryMatcher - the predicate to evaluate if retry should occur based on a given error signal

Returns:

a Flux that retries on onError up to the specified number of retry attempts, only if the predicate matches.

retryWhen

public final Flux<T> retryWhen(Function<Flux<Throwable>,? extends Publisher<?>> whenFactory)

Retries this Flux when a companion sequence signals an item in response to this Flux error signal

If the companion sequence signals when the Flux is active, the retry attempt is suppressed and any terminal signal will terminate the Flux source with the same signal immediately.

Note that if the companion Publisher created by the whenFactory emits Context as trigger objects, these Context will REPLACE the operator's own Context. Please be careful there: replacing the Context means that some keys you don't own could be removed, breaking libraries that depend on them. As a result, the recommended approach is to always create such a Context trigger by starting from the original Context (ensuring the trigger contains all the keys from the original, unless you absolutely know you want to remove one of these keys):

 .retryWhen(errorCurrentAttempt -> errorCurrentAttempt
     .flatMap(e -> Mono.subscriberContext().map(ctx -> Tuples.of(e, ctx)))
     .flatMap(t2 -> {
            Throwable lastError = t2.getT1();
            Context ctx = t2.getT2();
            int rl = ctx.getOrDefault("retriesLeft", 0);
            if (rl > 0) {
                    // /!\ THE ctx.put HERE IS THE ESSENTIAL PART /!\
                    return Mono.just(ctx.put("retriesLeft", rl - 1)
                                    .put("lastError", lastError));
            } else {
                    return Mono.error(new IllegalStateException("retries exhausted", lastError));
            }
     })
 )
 

Parameters:

whenFactory - the Function that returns the associated Publisher companion, given a Flux that signals each onError as a Throwable.

Returns:

a Flux that retries on onError when the companion Publisher produces an onNext signal

sample

public final Flux<T> sample(Duration timespan)

Sample this Flux by periodically emitting an item corresponding to that Flux latest emitted value within the periodical time window. Note that if some elements are emitted quicker than the timespan just before source completion, the last of these elements will be emitted along with the onComplete signal.

Parameters:

timespan - the duration of the window after which to emit the latest observed item

Returns:

a Flux sampled to the last item seen over each periodic window

sample

public final <U> Flux<T> sample(Publisher<U> sampler)

Sample this Flux by emitting an item corresponding to that Flux latest emitted value whenever a companion sampler Publisher signals a value.

Termination of either Publisher will result in termination for the Subscriber as well. Note that if some elements are emitted just before source completion and before a last sampler can trigger, the last of these elements will be emitted along with the onComplete signal.

Both Publisher will run in unbounded mode because the backpressure would interfere with the sampling precision.

Type Parameters:

U - the type of the sampler sequence

Parameters:

sampler - the sampler companion Publisher

Returns:

a Flux sampled to the last item observed each time the sampler Publisher signals

sampleFirst

public final Flux<T> sampleFirst(Duration timespan)

Repeatedly take a value from this Flux then skip the values that follow within a given duration.

Parameters:

timespan - the duration during which to skip values after each sample

Returns:

a Flux sampled to the first item of each duration-based window

sampleFirst

public final <U> Flux<T> sampleFirst(Function<? super T,? extends Publisher<U>> samplerFactory)

Repeatedly take a value from this Flux then skip the values that follow before the next signal from a companion sampler Publisher.

Type Parameters:

U - the companion reified type

Parameters:

samplerFactory - supply a companion sampler Publisher which signals the end of the skip window

Returns:

a Flux sampled to the first item observed in each window closed by the sampler signals

sampleTimeout

public final <U> Flux<T> sampleTimeout(Function<? super T,? extends Publisher<U>> throttlerFactory)

Emit the latest value from this Flux only if there were no new values emitted during the window defined by a companion Publisher derived from that particular value.

Note that this means that the last value in the sequence is always emitted.

Type Parameters:

U - the companion reified type

Parameters:

throttlerFactory - supply a companion sampler Publisher which signals the end of the window during which no new emission should occur. If it is the case, the original value triggering the window is emitted.

Returns:

a Flux sampled to items not followed by any other item within a window defined by a companion Publisher

sampleTimeout

public final <U> Flux<T> sampleTimeout(Function<? super T,? extends Publisher<U>> throttlerFactory,
                                       int maxConcurrency)

Emit the latest value from this Flux only if there were no new values emitted during the window defined by a companion Publisher derived from that particular value.

The provided maxConcurrency will keep a bounded maximum of concurrent timeouts and drop any new items until at least one timeout terminates.

Note that this means that the last value in the sequence is always emitted.

Type Parameters:

U - the throttling type

Parameters:

throttlerFactory - supply a companion sampler Publisher which signals the end of the window during which no new emission should occur. If it is the case, the original value triggering the window is emitted.

maxConcurrency - the maximum number of concurrent timeouts

Returns:

a Flux sampled to items not followed by any other item within a window defined by a companion Publisher

scan

public final Flux<T> scan(BiFunction<T,T,T> accumulator)

Reduce this Flux values with an accumulator BiFunction and also emit the intermediate results of this function.

Unlike scan(Object, BiFunction), this operator doesn't take an initial value but treats the first Flux value as initial value.
The accumulation works as follows:

 result[0] = source[0]
 result[1] = accumulator(result[0], source[1])
 result[2] = accumulator(result[1], source[2])
 result[3] = accumulator(result[2], source[3])
 ...
 

Parameters:

accumulator - the accumulating BiFunction

Returns:

an accumulating Flux

scan

public final <A> Flux<A> scan(A initial,
                              BiFunction<A,? super T,A> accumulator)

Reduce this Flux values with an accumulator BiFunction and also emit the intermediate results of this function.

The accumulation works as follows:

 result[0] = initialValue;
 result[1] = accumulator(result[0], source[0])
 result[2] = accumulator(result[1], source[1])
 result[3] = accumulator(result[2], source[2])
 ...
 

Type Parameters:

A - the accumulated type

Parameters:

initial - the initial leftmost argument to pass to the reduce function

accumulator - the accumulating BiFunction

Returns:

an accumulating Flux starting with initial state

scanWith

public final <A> Flux<A> scanWith(Supplier<A> initial,
                                  BiFunction<A,? super T,A> accumulator)

Reduce this Flux values with the help of an accumulator BiFunction and also emits the intermediate results. A seed value is lazily provided by a Supplier invoked for each Subscriber.

The accumulation works as follows:

 result[0] = initialValue;
 result[1] = accumulator(result[0], source[0])
 result[2] = accumulator(result[1], source[1])
 result[3] = accumulator(result[2], source[2])
 ...
 

Type Parameters:

A - the accumulated type

Parameters:

initial - the supplier providing the seed, the leftmost parameter initially passed to the reduce function

accumulator - the accumulating BiFunction

Returns:

an accumulating Flux starting with initial state

share

public final Flux<T> share()

Returns a new Flux that multicasts (shares) the original Flux. As long as there is at least one Subscriber this Flux will be subscribed and emitting data. When all subscribers have cancelled it will cancel the source Flux.

This is an alias for publish().ConnectableFlux.refCount().

Returns:

a Flux that upon first subscribe causes the source Flux to subscribe once, late subscribers might therefore miss items.

single

public final Mono<T> single()

Expect and emit a single item from this Flux source or signal NoSuchElementException for an empty source, or IndexOutOfBoundsException for a source with more than one element.

Returns:

a Mono with the single item or an error signal

single

public final Mono<T> single(T defaultValue)

Expect and emit a single item from this Flux source and emit a default value for an empty source, but signal an IndexOutOfBoundsException for a source with more than one element.

Parameters:

defaultValue - a single fallback item if this Flux is empty

Returns:

a Mono with the expected single item, the supplied default value or and error signal

singleOrEmpty

public final Mono<T> singleOrEmpty()

Expect and emit a single item from this Flux source, and accept an empty source but signal an IndexOutOfBoundsException for a source with more than one element.

Returns:

a Mono with the expected single item, no item or an error

skip

public final Flux<T> skip(long skipped)

Skip the specified number of elements from the beginning of this Flux then emit the remaining elements.

Parameters:

skipped - the number of elements to drop

Returns:

a dropping Flux with the specified number of elements skipped at the beginning

skip

public final Flux<T> skip(Duration timespan)

Skip elements from this Flux emitted within the specified initial duration.

Parameters:

timespan - the initial time window during which to drop elements

Returns:

a Flux dropping at the beginning until the end of the given duration

skip

public final Flux<T> skip(Duration timespan,
                          Scheduler timer)

Skip elements from this Flux emitted within the specified initial duration, as measured on the provided Scheduler.

Parameters:

timespan - the initial time window during which to drop elements

timer - a time-capable Scheduler instance to measure the time window on

Returns:

a Flux dropping at the beginning for the given duration

skipLast

public final Flux<T> skipLast(int n)

Skip a specified number of elements at the end of this Flux sequence.

Parameters:

n - the number of elements to drop before completion

Returns:

a Flux dropping the specified number of elements at the end of the sequence

skipUntil

public final Flux<T> skipUntil(Predicate<? super T> untilPredicate)

Skips values from this Flux until a Predicate returns true for the value. The resulting Flux will include and emit the matching value.

Parameters:

untilPredicate - the Predicate evaluated to stop skipping.

Returns:

a Flux dropping until the Predicate matches

skipUntilOther

public final Flux<T> skipUntilOther(Publisher<?> other)

Skip values from this Flux until a specified Publisher signals an onNext or onComplete.

Parameters:

other - the companion Publisher to coordinate with to stop skipping

Returns:

a Flux dropping until the other Publisher emits

skipWhile

public final Flux<T> skipWhile(Predicate<? super T> skipPredicate)

Skips values from this Flux while a Predicate returns true for the value.

Parameters:

skipPredicate - the Predicate that causes skipping while evaluating to true.

Returns:

a Flux dropping while the Predicate matches

sort

public final Flux<T> sort()

Sort elements from this Flux by collecting and sorting them in the background then emitting the sorted sequence once this sequence completes. Each item emitted by the Flux must implement Comparable with respect to all other items in the sequence.

Note that calling sort with long, non-terminating or infinite sources might cause OutOfMemoryError. Use sequence splitting like window(int) to sort batches in that case.

Returns:

a sorted Flux

Throws:

ClassCastException - if any item emitted by the Flux does not implement Comparable with respect to all other items emitted by the Flux

sort

public final Flux<T> sort(Comparator<? super T> sortFunction)

Sort elements from this Flux using a Comparator function, by collecting and sorting elements in the background then emitting the sorted sequence once this sequence completes.

Note that calling sort with long, non-terminating or infinite sources might cause OutOfMemoryError

Parameters:

sortFunction - a function that compares two items emitted by this Flux to indicate their sort order

Returns:

a sorted Flux

startWith

public final Flux<T> startWith(Iterable<? extends T> iterable)

Prepend the given Iterable before this Flux sequence.

Parameters:

iterable - the sequence of values to start the resulting Flux with

Returns:

a new Flux prefixed with elements from an Iterable

startWith

@SafeVarargs
public final Flux<T> startWith(T... values)

Prepend the given values before this Flux sequence.

Parameters:

values - the array of values to start the resulting Flux with

Returns:

a new Flux prefixed with the given elements

startWith

public final Flux<T> startWith(Publisher<? extends T> publisher)

Prepend the given Publisher sequence to this Flux sequence.

Parameters:

publisher - the Publisher whose values to prepend

Returns:

a new Flux prefixed with the given Publisher sequence

subscribe

public final Disposable subscribe()

Subscribe to this Flux and request unbounded demand.

This version doesn't specify any consumption behavior for the events from the chain, especially no error handling, so other variants should usually be preferred.

Returns:

a new Disposable that can be used to cancel the underlying Subscription

subscribe

public final Disposable subscribe(Consumer<? super T> consumer)

Subscribe a Consumer to this Flux that will consume all the elements in the sequence. It will request an unbounded demand (Long.MAX_VALUE).

For a passive version that observe and forward incoming data see doOnNext(java.util.function.Consumer).

For a version that gives you more control over backpressure and the request, see subscribe(Subscriber) with a BaseSubscriber.

Keep in mind that since the sequence can be asynchronous, this will immediately return control to the calling thread. This can give the impression the consumer is not invoked when executing in a main thread or a unit test for instance.

Parameters:

consumer - the consumer to invoke on each value (onNext signal)

Returns:

a new Disposable that can be used to cancel the underlying Subscription

subscribe

public final Disposable subscribe(@Nullable
                                  Consumer<? super T> consumer,
                                  Consumer<? super Throwable> errorConsumer)

Subscribe to this Flux with a Consumer that will consume all the elements in the sequence, as well as a Consumer that will handle errors. The subscription will request an unbounded demand (Long.MAX_VALUE).

For a passive version that observe and forward incoming data see doOnNext(java.util.function.Consumer) and doOnError(java.util.function.Consumer).

For a version that gives you more control over backpressure and the request, see subscribe(Subscriber) with a BaseSubscriber.

Keep in mind that since the sequence can be asynchronous, this will immediately return control to the calling thread. This can give the impression the consumers are not invoked when executing in a main thread or a unit test for instance.

Parameters:

consumer - the consumer to invoke on each next signal

errorConsumer - the consumer to invoke on error signal

Returns:

a new Disposable that can be used to cancel the underlying Subscription

subscribe

public final Disposable subscribe(@Nullable
                                  Consumer<? super T> consumer,
                                  @Nullable
                                  Consumer<? super Throwable> errorConsumer,
                                  @Nullable
                                  Runnable completeConsumer)

Subscribe Consumer to this Flux that will respectively consume all the elements in the sequence, handle errors and react to completion. The subscription will request unbounded demand (Long.MAX_VALUE).

For a passive version that observe and forward incoming data see doOnNext(java.util.function.Consumer), doOnError(java.util.function.Consumer) and doOnComplete(Runnable).

For a version that gives you more control over backpressure and the request, see subscribe(Subscriber) with a BaseSubscriber.

Keep in mind that since the sequence can be asynchronous, this will immediately return control to the calling thread. This can give the impression the consumer is not invoked when executing in a main thread or a unit test for instance.

Parameters:

consumer - the consumer to invoke on each value

errorConsumer - the consumer to invoke on error signal

completeConsumer - the consumer to invoke on complete signal

Returns:

a new Disposable that can be used to cancel the underlying Subscription

subscribe

public final Disposable subscribe(@Nullable
                                  Consumer<? super T> consumer,
                                  @Nullable
                                  Consumer<? super Throwable> errorConsumer,
                                  @Nullable
                                  Runnable completeConsumer,
                                  @Nullable
                                  Consumer<? super Subscription> subscriptionConsumer)

Subscribe Consumer to this Flux that will respectively consume all the elements in the sequence, handle errors, react to completion, and request upon subscription. It will let the provided subscriptionConsumer request the adequate amount of data, or request unbounded demand Long.MAX_VALUE if no such consumer is provided.

For a passive version that observe and forward incoming data see doOnNext(java.util.function.Consumer), doOnError(java.util.function.Consumer), doOnComplete(Runnable) and doOnSubscribe(Consumer).

For a version that gives you more control over backpressure and the request, see subscribe(Subscriber) with a BaseSubscriber.

Keep in mind that since the sequence can be asynchronous, this will immediately return control to the calling thread. This can give the impression the consumer is not invoked when executing in a main thread or a unit test for instance.

Parameters:

consumer - the consumer to invoke on each value

errorConsumer - the consumer to invoke on error signal

completeConsumer - the consumer to invoke on complete signal

subscriptionConsumer - the consumer to invoke on subscribe signal, to be used for the initial request, or null for max request

Returns:

a new Disposable that can be used to cancel the underlying Subscription

subscribe

public final void subscribe(Subscriber<? super T> actual)

Specified by:

subscribe in interface Publisher<T>

subscribe

public abstract void subscribe(CoreSubscriber<? super T> actual)

An internal Publisher.subscribe(Subscriber) that will bypass Hooks.onLastOperator(Function) pointcut.

In addition to behave as expected by Publisher.subscribe(Subscriber) in a controlled manner, it supports direct subscribe-time Context passing.

Parameters:

actual - the Subscriber interested into the published sequence

See Also:

subscribe(Subscriber)

subscriberContext

public final Flux<T> subscriberContext(Context mergeContext)

Enrich a potentially empty downstream Context by adding all values from the given Context, producing a new Context that is propagated upstream.

The Context propagation happens once per subscription (not on each onNext): it is done during the subscribe(Subscriber) phase, which runs from the last operator of a chain towards the first.

So this operator enriches a Context coming from under it in the chain (downstream, by default an empty one) and passes the new enriched Context to operators above it in the chain (upstream, by way of them using Flux#subscribe(Subscriber,Context)).

Parameters:

mergeContext - the Context to merge with a previous Context state, returning a new one.

Returns:

a contextualized Flux

See Also:

Context

subscriberContext

public final Flux<T> subscriberContext(Function<Context,Context> doOnContext)

Enrich a potentially empty downstream Context by applying a Function to it, producing a new Context that is propagated upstream.

The Context propagation happens once per subscription (not on each onNext): it is done during the subscribe(Subscriber) phase, which runs from the last operator of a chain towards the first.

So this operator enriches a Context coming from under it in the chain (downstream, by default an empty one) and passes the new enriched Context to operators above it in the chain (upstream, by way of them using Flux#subscribe(Subscriber,Context)).

Parameters:

doOnContext - the function taking a previous Context state and returning a new one.

Returns:

a contextualized Flux

See Also:

Context

subscribeOn

public final Flux<T> subscribeOn(Scheduler scheduler)

Run subscribe, onSubscribe and request on a specified Scheduler's Scheduler.Worker. As such, placing this operator anywhere in the chain will also impact the execution context of onNext/onError/onComplete signals from the beginning of the chain up to the next occurrence of a publishOn.

Note that if you are using an eager or blocking create(Consumer, FluxSink.OverflowStrategy) as the source, it can lead to deadlocks due to requests piling up behind the emitter. In such case, you should call subscribeOn(scheduler, false) instead.

Typically used for slow publisher e.g., blocking IO, fast consumer(s) scenarios.

  flux.subscribeOn(Schedulers.single()).subscribe() 
 

Note that Scheduler.Worker.schedule(Runnable) raising RejectedExecutionException on late Subscription.request(long) will be propagated to the request caller.

Parameters:

scheduler - a Scheduler providing the Scheduler.Worker where to subscribe

Returns:

a Flux requesting asynchronously

See Also:

publishOn(Scheduler), subscribeOn(Scheduler, boolean)

subscribeOn

public final Flux<T> subscribeOn(Scheduler scheduler,
                                 boolean requestOnSeparateThread)

Run subscribe and onSubscribe on a specified Scheduler's Scheduler.Worker. Request will be run on that worker too depending on the requestOnSeparateThread parameter (which defaults to true in the subscribeOn(Scheduler) version). As such, placing this operator anywhere in the chain will also impact the execution context of onNext/onError/onComplete signals from the beginning of the chain up to the next occurrence of a publishOn.

Note that if you are using an eager or blocking create(Consumer, FluxSink.OverflowStrategy) as the source, it can lead to deadlocks due to requests piling up behind the emitter. Thus this operator has a requestOnSeparateThread parameter, which should be set to false in this case.

Typically used for slow publisher e.g., blocking IO, fast consumer(s) scenarios.

  flux.subscribeOn(Schedulers.single()).subscribe() 
 

Note that Scheduler.Worker.schedule(Runnable) raising RejectedExecutionException on late Subscription.request(long) will be propagated to the request caller.

Parameters:

scheduler - a Scheduler providing the Scheduler.Worker where to subscribe

requestOnSeparateThread - whether or not to also perform requests on the worker. true to behave like subscribeOn(Scheduler)

Returns:

a Flux requesting asynchronously

See Also:

publishOn(Scheduler), subscribeOn(Scheduler)

subscribeWith

public final <E extends Subscriber<? super T>> E subscribeWith(E subscriber)

Subscribe the given Subscriber to this Flux and return said Subscriber (eg. a FluxProcessor).

  flux.subscribeWith(WorkQueueProcessor.create()).subscribe() 
 

If you need more control over backpressure and the request, use a BaseSubscriber.

Type Parameters:

E - the reified type from the input/output subscriber

Parameters:

subscriber - the Subscriber to subscribe with and return

Returns:

the passed Subscriber

switchIfEmpty

public final Flux<T> switchIfEmpty(Publisher<? extends T> alternate)

Switch to an alternative Publisher if this sequence is completed without any data.

Parameters:

alternate - the alternative Publisher if this sequence is empty

Returns:

a new Flux that falls back on a Publisher if source is empty

switchMap

public final <V> Flux<V> switchMap(Function<? super T,Publisher<? extends V>> fn)

Switch to a new Publisher generated via a Function whenever this Flux produces an item. As such, the elements from each generated Publisher are emitted in the resulting Flux.

Type Parameters:

V - the type of the return value of the transformation function

Parameters:

fn - the Function to generate a Publisher for each source value

Returns:

a new Flux that emits values from an alternative Publisher for each source onNext

switchMap

public final <V> Flux<V> switchMap(Function<? super T,Publisher<? extends V>> fn,
                                   int prefetch)

Switch to a new Publisher generated via a Function whenever this Flux produces an item. As such, the elements from each generated Publisher are emitted in the resulting Flux.

Type Parameters:

V - the type of the return value of the transformation function

Parameters:

fn - the Function to generate a Publisher for each source value

prefetch - the produced demand for inner sources

Returns:

a new Flux that emits values from an alternative Publisher for each source onNext

tag

public final Flux<T> tag(String key,
                         String value)

Tag this flux with a key/value pair. These can be retrieved as a Set of all tags throughout the publisher chain by using Scannable.tags() (as traversed by Scannable.parents()).

Parameters:

key - a tag key

value - a tag value

Returns:

the same sequence, but bearing tags

take

public final Flux<T> take(long n)

Take only the first N values from this Flux, if available.

If N is zero, the resulting Flux completes as soon as this Flux signals its first value (which is not not relayed, though).

Note that this operator doesn't manipulate the backpressure requested amount. Rather, it merely lets requests from downstream propagate as is and cancels once N elements have been emitted. As a result, the source could produce a lot of extraneous elements in the meantime. If that behavior is undesirable and you do not own the request from downstream (e.g. prefetching operators), consider using limitRequest(long) instead.

Parameters:

n - the number of items to emit from this Flux

Returns:

a Flux limited to size N

See Also:

limitRequest(long)

take

public final Flux<T> take(Duration timespan)

Relay values from this Flux until the specified Duration elapses.

If the duration is zero, the resulting Flux completes as soon as this Flux signals its first value (which is not not relayed, though).

Parameters:

timespan - the Duration of the time window during which to emit elements from this Flux

Returns:

a Flux limited to elements emitted within a specific duration

take

public final Flux<T> take(Duration timespan,
                          Scheduler timer)

Relay values from this Flux until the specified Duration elapses, as measured on the specified Scheduler.

If the duration is zero, the resulting Flux completes as soon as this Flux signals its first value (which is not not relayed, though).

Parameters:

timespan - the Duration of the time window during which to emit elements from this Flux

timer - a time-capable Scheduler instance to run on

Returns:

a Flux limited to elements emitted within a specific duration

takeLast

public final Flux<T> takeLast(int n)

Emit the last N values this Flux emitted before its completion.

Parameters:

n - the number of items from this Flux to retain and emit on onComplete

Returns:

a terminating Flux sub-sequence

takeUntil

public final Flux<T> takeUntil(Predicate<? super T> predicate)

Relay values from this Flux until the given Predicate matches. This includes the matching data (unlike takeWhile(java.util.function.Predicate<? super T>)).

Parameters:

predicate - the Predicate that stops the taking of values from this Flux when returning true.

Returns:

a new Flux limited by the predicate

takeUntilOther

public final Flux<T> takeUntilOther(Publisher<?> other)

Relay values from this Flux until the given Publisher emits.

Parameters:

other - the companion Publisher that signals when to stop taking values from this Flux

Returns:

a new Flux limited by a companion Publisher

takeWhile

public final Flux<T> takeWhile(Predicate<? super T> continuePredicate)

Relay values from this Flux while a predicate returns TRUE for the values (checked before each value is delivered). This only includes the matching data (unlike takeUntil(java.util.function.Predicate<? super T>)).

Parameters:

continuePredicate - the Predicate invoked each onNext returning TRUE to relay a value or FALSE to terminate

Returns:

a new Flux taking values from the source while the predicate matches

then

public final Mono<Void> then()

Return a Mono<Void> that completes when this Flux completes. This will actively ignore the sequence and only replay completion or error signals.

Returns:

a new Mono representing the termination of this Flux

then

public final <V> Mono<V> then(Mono<V> other)

Let this Flux complete then play signals from a provided Mono.

In other words ignore element from this Flux and transform its completion signal into the emission and completion signal of a provided Mono<V>. Error signal is replayed in the resulting Mono<V>.

Type Parameters:

V - the element type of the supplied Mono

Parameters:

other - a Mono to emit from after termination

Returns:

a new Flux that wait for source completion then emits from the supplied Mono

thenEmpty

public final Mono<Void> thenEmpty(Publisher<Void> other)

Return a Mono<Void> that waits for this Flux to complete then for a supplied Publisher<Void> to also complete. The second completion signal is replayed, or any error signal that occurs instead.

Parameters:

other - a Publisher to wait for after this Flux's termination

Returns:

a new Mono completing when both publishers have completed in sequence

thenMany

public final <V> Flux<V> thenMany(Publisher<V> other)

Let this Flux complete then play another Publisher.

In other words ignore element from this flux and transform the completion signal into a Publisher<V> that will emit elements from the provided Publisher.

Type Parameters:

V - the element type of the supplied Publisher

Parameters:

other - a Publisher to emit from after termination

Returns:

a new Flux that emits from the supplied Publisher after this Flux completes.

timeout

public final Flux<T> timeout(Duration timeout)

Propagate a TimeoutException as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item).

Parameters:

timeout - the timeout between two signals from this Flux

Returns:

a Flux that can time out on a per-item basis

timeout

public final Flux<T> timeout(Duration timeout,
                             @Nullable
                             Publisher<? extends T> fallback)

Switch to a fallback Flux as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item).

If the given Publisher is null, signal a TimeoutException instead.

Parameters:

timeout - the timeout between two signals from this Flux

fallback - the fallback Publisher to subscribe when a timeout occurs

Returns:

a Flux that will fallback to a different Publisher in case of a per-item timeout

timeout

public final Flux<T> timeout(Duration timeout,
                             Scheduler timer)

Propagate a TimeoutException as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item), as measured by the specified Scheduler.

Parameters:

timeout - the timeout Duration between two signals from this Flux

timer - a time-capable Scheduler instance to run on

Returns:

a Flux that can time out on a per-item basis

timeout

public final Flux<T> timeout(Duration timeout,
                             @Nullable
                             Publisher<? extends T> fallback,
                             Scheduler timer)

Switch to a fallback Flux as soon as no item is emitted within the given Duration from the previous emission (or the subscription for the first item), as measured on the specified Scheduler.

If the given Publisher is null, signal a TimeoutException instead.

Parameters:

timeout - the timeout Duration between two signals from this Flux

fallback - the fallback Publisher to subscribe when a timeout occurs

timer - a time-capable Scheduler instance to run on

Returns:

a Flux that will fallback to a different Publisher in case of a per-item timeout

timeout

public final <U> Flux<T> timeout(Publisher<U> firstTimeout)

Signal a TimeoutException in case the first item from this Flux has not been emitted before the given Publisher emits.

Type Parameters:

U - the type of the timeout Publisher

Parameters:

firstTimeout - the companion Publisher that will trigger a timeout if emitting before the first signal from this Flux

Returns:

a Flux that can time out if the first item does not come before a signal from a companion Publisher

timeout

public final <U,V> Flux<T> timeout(Publisher<U> firstTimeout,
                                   Function<? super T,? extends Publisher<V>> nextTimeoutFactory)

Signal a TimeoutException in case the first item from this Flux has not been emitted before the firstTimeout Publisher emits, and whenever each subsequent elements is not emitted before a Publisher generated from the latest element signals.

Type Parameters:

U - the type of the elements of the first timeout Publisher

V - the type of the elements of the subsequent timeout Publishers

Parameters:

firstTimeout - the timeout Publisher that must not emit before the first signal from this Flux

nextTimeoutFactory - the timeout Publisher factory for each next item

Returns:

a Flux that can time out if each element does not come before a signal from a per-item companion Publisher

timeout

public final <U,V> Flux<T> timeout(Publisher<U> firstTimeout,
                                   Function<? super T,? extends Publisher<V>> nextTimeoutFactory,
                                   Publisher<? extends T> fallback)

Switch to a fallback Publisher in case the first item from this Flux has not been emitted before the firstTimeout Publisher emits, and whenever each subsequent elements is not emitted before a Publisher generated from the latest element signals.

Type Parameters:

U - the type of the elements of the first timeout Publisher

V - the type of the elements of the subsequent timeout Publishers

Parameters:

firstTimeout - the timeout Publisher that must not emit before the first signal from this Flux

nextTimeoutFactory - the timeout Publisher factory for each next item

fallback - the fallback Publisher to subscribe when a timeout occurs

Returns:

a Flux that can time out if each element does not come before a signal from a per-item companion Publisher

timestamp

public final Flux<Tuple2<Long,T>> timestamp()

Emit a Tuple2 pair of T1 the current clock time in millis (as a Long measured by the parallel Scheduler) and T2 the emitted data (as a T), for each item from this Flux.

Returns:

a timestamped Flux

timestamp

public final Flux<Tuple2<Long,T>> timestamp(Scheduler scheduler)

Emit a Tuple2 pair of T1 the current clock time in millis (as a Long measured by the provided Scheduler) and T2 the emitted data (as a T), for each item from this Flux.

Parameters:

scheduler - the Scheduler to read time from

Returns:

a timestamped Flux

toIterable

public final Iterable<T> toIterable()

Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.

Returns:

a blocking Iterable

toIterable

public final Iterable<T> toIterable(int batchSize)

Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.

Parameters:

batchSize - the bounded capacity to prefetch from this Flux or Integer.MAX_VALUE for unbounded demand

Returns:

a blocking Iterable

toIterable

public final Iterable<T> toIterable(int batchSize,
                                    @Nullable
                                    Supplier<Queue<T>> queueProvider)

Transform this Flux into a lazy Iterable blocking on Iterator.next() calls.

Parameters:

batchSize - the bounded capacity to prefetch from this Flux or Integer.MAX_VALUE for unbounded demand

queueProvider - the supplier of the queue implementation to be used for storing elements emitted faster than the iteration

Returns:

a blocking Iterable

toStream

public final Stream<T> toStream()

Transform this Flux into a lazy Stream blocking for each source onNext call.

Returns:

a Stream of unknown size with onClose attached to Subscription.cancel()

toStream

public final Stream<T> toStream(int batchSize)

Transform this Flux into a lazy Stream blocking for each source onNext call.

Parameters:

batchSize - the bounded capacity to prefetch from this Flux or Integer.MAX_VALUE for unbounded demand

Returns:

a Stream of unknown size with onClose attached to Subscription.cancel()

transform

public final <V> Flux<V> transform(Function<? super Flux<T>,? extends Publisher<V>> transformer)

Transform this Flux in order to generate a target Flux. Unlike compose(Function), the provided function is executed as part of assembly.

 
 Function<Flux, Flux> applySchedulers = flux -> flux.subscribeOn(Schedulers.elastic())
                                                    .publishOn(Schedulers.parallel());
 flux.transform(applySchedulers).map(v -> v * v).subscribe();
 

Type Parameters:

V - the item type in the returned Flux

Parameters:

transformer - the Function to immediately map this Flux into a target Flux instance.

Returns:

a new Flux

See Also:

for deferred composition of {@link Flux} for each {@link Subscriber}, for a loose conversion to an arbitrary type

window

public final Flux<Flux<T>> window(int maxSize)

Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item. Each Flux window will onComplete after maxSize items have been routed.

Parameters:

maxSize - the maximum number of items to emit in the window before closing it

Returns:

a Flux of Flux windows based on element count

window

public final Flux<Flux<T>> window(int maxSize,
                                  int skip)

Split this Flux sequence into multiple Flux windows of size maxSize, that each open every skip elements in the source.

When maxSize < skip : dropping windows

When maxSize > skip : overlapping windows

When maxSize == skip : exact windows

Parameters:

maxSize - the maximum number of items to emit in the window before closing it

skip - the number of items to count before opening and emitting a new window

Returns:

a Flux of Flux windows based on element count and opened every skipCount

window

public final Flux<Flux<T>> window(Publisher<?> boundary)

Split this Flux sequence into continuous, non-overlapping windows where the window boundary is signalled by another Publisher

Parameters:

boundary - a Publisher to emit any item for a split signal and complete to terminate

Returns:

a Flux of Flux windows delimited by a given Publisher

window

public final Flux<Flux<T>> window(Duration timespan)

Split this Flux sequence into continuous, non-overlapping windows that open for a timespan Duration (as measured on the parallel Scheduler).

Parameters:

timespan - the Duration to delimit Flux windows

Returns:

a Flux of Flux windows continuously opened for a given Duration

window

public final Flux<Flux<T>> window(Duration timespan,
                                  Duration timeshift)

Split this Flux sequence into multiple Flux windows that open for a given timespan Duration, after which it closes with onComplete. Each window is opened at a regular timeShift interval, starting from the first item. Both durations are measured on the parallel Scheduler.

When timespan < timeshift : dropping windows

When timespan > timeshift : overlapping windows

When timespan == timeshift : exact windows

Parameters:

timespan - the maximum Flux window Duration

timeshift - the period of time at which to create new Flux windows

Returns:

a Flux of Flux windows opened at regular intervals and closed after a Duration

window

public final Flux<Flux<T>> window(Duration timespan,
                                  Scheduler timer)

Split this Flux sequence into continuous, non-overlapping windows that open for a timespan Duration (as measured on the provided Scheduler).

Parameters:

timespan - the Duration to delimit Flux windows

timer - a time-capable Scheduler instance to run on

Returns:

a Flux of Flux windows continuously opened for a given Duration

window

public final Flux<Flux<T>> window(Duration timespan,
                                  Duration timeshift,
                                  Scheduler timer)

Split this Flux sequence into multiple Flux windows that open for a given timespan Duration, after which it closes with onComplete. Each window is opened at a regular timeShift interval, starting from the first item. Both durations are measured on the provided Scheduler.

When timespan < timeshift : dropping windows

When timespan > timeshift : overlapping windows

When timeshift == timeshift : exact windows

Parameters:

timespan - the maximum Flux window Duration

timeshift - the period of time at which to create new Flux windows

timer - a time-capable Scheduler instance to run on

Returns:

a Flux of Flux windows opened at regular intervals and closed after a Duration

windowTimeout

public final Flux<Flux<T>> windowTimeout(int maxSize,
                                         Duration timespan)

Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item. Each Flux window will onComplete once it contains maxSize elements OR it has been open for the given Duration (as measured on the parallel Scheduler).

Parameters:

maxSize - the maximum number of items to emit in the window before closing it

timespan - the maximum Duration since the window was opened before closing it

Returns:

a Flux of Flux windows based on element count and duration

windowTimeout

public final Flux<Flux<T>> windowTimeout(int maxSize,
                                         Duration timespan,
                                         Scheduler timer)

Split this Flux sequence into multiple Flux windows containing maxSize elements (or less for the final window) and starting from the first item. Each Flux window will onComplete once it contains maxSize elements OR it has been open for the given Duration (as measured on the provided Scheduler).

Parameters:

maxSize - the maximum number of items to emit in the window before closing it

timespan - the maximum Duration since the window was opened before closing it

timer - a time-capable Scheduler instance to run on

Returns:

a Flux of Flux windows based on element count and duration

windowUntil

public final Flux<Flux<T>> windowUntil(Predicate<T> boundaryTrigger)

Split this Flux sequence into multiple Flux windows delimited by the given predicate. A new window is opened each time the predicate returns true, at which point the previous window will receive the triggering element then onComplete.

Parameters:

boundaryTrigger - a predicate that triggers the next window when it becomes true.

Returns:

a Flux of Flux windows, bounded depending on the predicate.

windowUntil

public final Flux<Flux<T>> windowUntil(Predicate<T> boundaryTrigger,
                                       boolean cutBefore)

Split this Flux sequence into multiple Flux windows delimited by the given predicate. A new window is opened each time the predicate returns true.

If cutBefore is true, the old window will onComplete and the triggering element will be emitted in the new window. Note it can mean that an empty window is sometimes emitted, eg. if the first element in the sequence immediately matches the predicate.

Otherwise, the triggering element will be emitted in the old window before it does onComplete, similar to windowUntil(Predicate).

Parameters:

boundaryTrigger - a predicate that triggers the next window when it becomes true.

cutBefore - push to true to include the triggering element in the new window rather than the old.

Returns:

a Flux of Flux windows, bounded depending on the predicate.

windowUntil

public final Flux<Flux<T>> windowUntil(Predicate<T> boundaryTrigger,
                                       boolean cutBefore,
                                       int prefetch)

Split this Flux sequence into multiple Flux windows delimited by the given predicate and using a prefetch. A new window is opened each time the predicate returns true.

If cutBefore is true, the old window will onComplete and the triggering element will be emitted in the new window. Note it can mean that an empty window is sometimes emitted, eg. if the first element in the sequence immediately matches the predicate.

Otherwise, the triggering element will be emitted in the old window before it does onComplete, similar to windowUntil(Predicate).

Parameters:

boundaryTrigger - a predicate that triggers the next window when it becomes true.

cutBefore - push to true to include the triggering element in the new window rather than the old.

prefetch - the request size to use for this Flux.

Returns:

a Flux of Flux windows, bounded depending on the predicate.

windowWhile

public final Flux<Flux<T>> windowWhile(Predicate<T> inclusionPredicate)

Split this Flux sequence into multiple Flux windows that stay open while a given predicate matches the source elements. Once the predicate returns false, the window closes with an onComplete and the triggering element is discarded.

Note that for a sequence starting with a separator, or having several subsequent separators anywhere in the sequence, each occurrence will lead to an empty window.

Parameters:

inclusionPredicate - a predicate that triggers the next window when it becomes false.

Returns:

a Flux of Flux windows, each containing subsequent elements that all passed a predicate.

windowWhile

public final Flux<Flux<T>> windowWhile(Predicate<T> inclusionPredicate,
                                       int prefetch)

Split this Flux sequence into multiple Flux windows that stay open while a given predicate matches the source elements. Once the predicate returns false, the window closes with an onComplete and the triggering element is discarded.

Note that for a sequence starting with a separator, or having several subsequent separators anywhere in the sequence, each occurrence will lead to an empty window.

Parameters:

inclusionPredicate - a predicate that triggers the next window when it becomes false.

prefetch - the request size to use for this Flux.

Returns:

a Flux of Flux windows, each containing subsequent elements that all passed a predicate.

windowWhen

public final <U,V> Flux<Flux<T>> windowWhen(Publisher<U> bucketOpening,
                                            Function<? super U,? extends Publisher<V>> closeSelector)

Split this Flux sequence into potentially overlapping windows controlled by items of a start Publisher and end Publisher derived from the start values.

When Open signal is strictly not overlapping Close signal : dropping windows

When Open signal is strictly more frequent than Close signal : overlapping windows

When Open signal is exactly coordinated with Close signal : exact windows

Type Parameters:

U - the type of the sequence opening windows

V - the type of the sequence closing windows opened by the bucketOpening Publisher's elements

Parameters:

bucketOpening - a Publisher that opens a new window when it emits any item

closeSelector - a Function given an opening signal and returning a Publisher that will close the window when emitting

Returns:

a Flux of Flux windows opened by signals from a first Publisher and lasting until a selected second Publisher emits

withLatestFrom

public final <U,R> Flux<R> withLatestFrom(Publisher<? extends U> other,
                                          BiFunction<? super T,? super U,? extends R> resultSelector)

Combine the most recently emitted values from both this Flux and another Publisher through a BiFunction and emits the result.

The operator will drop values from this Flux until the other Publisher produces any value.

If the other Publisher completes without any value, the sequence is completed.

Type Parameters:

U - the other Publisher sequence type

R - the result type

Parameters:

other - the Publisher to combine with

resultSelector - the bi-function called with each pair of source and other elements that should return a single value to be emitted

Returns:

a combined Flux gated by another Publisher

zipWith

public final <T2> Flux<Tuple2<T,T2>> zipWith(Publisher<? extends T2> source2)

Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements once into a Tuple2. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T2 - type of the value from source2

Parameters:

source2 - The second source Publisher to zip with this Flux.

Returns:

a zipped Flux

zipWith

public final <T2,V> Flux<V> zipWith(Publisher<? extends T2> source2,
                                    BiFunction<? super T,? super T2,? extends V> combinator)

Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements using a combinator BiFunction The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T2 - type of the value from source2

V - The produced output after transformation by the combinator

Parameters:

source2 - The second source Publisher to zip with this Flux.

combinator - The aggregate function that will receive a unique value from each source and return the value to signal downstream

Returns:

a zipped Flux

zipWith

public final <T2,V> Flux<V> zipWith(Publisher<? extends T2> source2,
                                    int prefetch,
                                    BiFunction<? super T,? super T2,? extends V> combinator)

Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements using a combinator BiFunction The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T2 - type of the value from source2

V - The produced output after transformation by the combinator

Parameters:

source2 - The second source Publisher to zip with this Flux.

prefetch - the request size to use for this Flux and the other Publisher

combinator - The aggregate function that will receive a unique value from each source and return the value to signal downstream

Returns:

a zipped Flux

zipWith

public final <T2> Flux<Tuple2<T,T2>> zipWith(Publisher<? extends T2> source2,
                                             int prefetch)

Zip this Flux with another Publisher source, that is to say wait for both to emit one element and combine these elements once into a Tuple2. The operator will continue doing so until any of the sources completes. Errors will immediately be forwarded. This "Step-Merge" processing is especially useful in Scatter-Gather scenarios.

Type Parameters:

T2 - type of the value from source2

Parameters:

source2 - The second source Publisher to zip with this Flux.

prefetch - the request size to use for this Flux and the other Publisher

Returns:

a zipped Flux

zipWithIterable

public final <T2> Flux<Tuple2<T,T2>> zipWithIterable(Iterable<? extends T2> iterable)

Zip elements from this Flux with the content of an Iterable, that is to say combine one element from each, pairwise, into a Tuple2.

Type Parameters:

T2 - the value type of the other iterable sequence

Parameters:

iterable - the Iterable to zip with

Returns:

a zipped Flux

zipWithIterable

public final <T2,V> Flux<V> zipWithIterable(Iterable<? extends T2> iterable,
                                            BiFunction<? super T,? super T2,? extends V> zipper)

Zip elements from this Flux with the content of an Iterable, that is to say combine one element from each, pairwise, using the given zipper BiFunction.

Type Parameters:

T2 - the value type of the other iterable sequence

V - the result type

Parameters:

iterable - the Iterable to zip with

zipper - the BiFunction pair combinator

Returns:

a zipped Flux

onAssembly

protected static <T> Flux<T> onAssembly(Flux<T> source)

To be used by custom operators: invokes assembly Hooks pointcut given a Flux, potentially returning a new Flux. This is for example useful to activate cross-cutting concerns at assembly time, eg. a generalized checkpoint().

Type Parameters:

T - the value type

Parameters:

source - the source to apply assembly hooks onto

Returns:

the source, potentially wrapped with assembly time cross-cutting behavior

onLastAssembly

protected static <T> Flux<T> onLastAssembly(Flux<T> source)

To be used by custom operators: invokes assembly Hooks pointcut given a Flux, potentially returning a new Flux. This is for example useful to activate cross-cutting concerns at assembly time, eg. a generalized checkpoint().

Type Parameters:

T - the value type

Parameters:

source - the source to apply assembly hooks onto

Returns:

the source, potentially wrapped with assembly time cross-cutting behavior

onAssembly

protected static <T> ConnectableFlux<T> onAssembly(ConnectableFlux<T> source)

To be used by custom operators: invokes assembly Hooks pointcut given a ConnectableFlux, potentially returning a new ConnectableFlux. This is for example useful to activate cross-cutting concerns at assembly time, eg. a generalized checkpoint().

Type Parameters:

T - the value type

Parameters:

source - the source to apply assembly hooks onto

Returns:

the source, potentially wrapped with assembly time cross-cutting behavior

toString

public String toString()

Overrides:

toString in class Object