Interface StreamSink<T>

Type Parameters:

T - the item type to be offered

All Known Subinterfaces:

StreamProcessor<In,Out>

All Known Implementing Classes:

DispatchStreamProcessor

public interface StreamSink<@NonNull T>

An interface to submit items and terminal events to a consumer that indacates when the processing of said item or terminal event has completed, similar to how Flow.Subscriber can receive events.

The general contract is to call next(Object) zero or more times, then call finish(Throwable) at most once, all in a non-overlapping fashion and only if the returned CompletionStage has completed in some fashion.

Since:

4.0.0

Method Summary

Modifier and Type	Method	Description
default @NonNull DisposableStreamerCancellation	cancellation()	Returns the DisposableContainer to use to detect if the consumer has indicated no more items it is willing to accept.
static <T> @NonNull StreamSink<T>	create(@NonNull Function<? super T, ? extends CompletionStage<Boolean>> onNext, @NonNull Function<? super Throwable, ? extends CompletionStage<Void>> onFinish)	Creates a StreamSink via lambda callbacks for next(Object) and finish(Throwable).
@NonNull CompletionStage<Void>	finish(@Nullable Throwable throwable)	Offer the final, terminal event.
@NonNull CompletionStage<Boolean>	next(@NonNull T item)	Offer the next item.
default @NonNull StreamSink<T>	withCancellation(DisposableStreamerCancellation cancellation)	Returns a new StreamSink that returns the given DisposableStreamerCancellation in its cancellation(), allowing overriding the cancellation management of this StreamSink

Method Details

next

@NonNull
@NonNull CompletionStage<Boolean> next(@NonNull T item)

Offer the next item.

Parameters:

item - the item being offered

Returns:

a CompletionStage that completes with true if the value was successfully consumed, false if the value was rejected or exceptionally on error

finish

@NonNull
@NonNull CompletionStage<Void> finish(@Nullable
 @Nullable Throwable throwable)

Offer the final, terminal event.

Parameters:

throwable - the optional throwable to signal error, null to signal normal completion

Returns:

a CompletionStage that completes with null if the call succeeded or exceptionally on error

cancellation

@NonNull
default @NonNull DisposableStreamerCancellation cancellation()

Returns the DisposableContainer to use to detect if the consumer has indicated no more items it is willing to accept.

The default implementation returns a fresh CompositeDisposable.

Returns:

the DisposableContainer

withCancellation

@NonNull
default @NonNull StreamSink<T> withCancellation(DisposableStreamerCancellation cancellation)

Returns a new StreamSink that returns the given DisposableStreamerCancellation in its cancellation(), allowing overriding the cancellation management of this StreamSink

Parameters:

cancellation - the DisposableStreamerCancellation to use as cancellation management

Returns:

the new StreamSink instance

Throws:

NullPointerException - if cancellation is null

create

@NonNull
static <T> @NonNull StreamSink<T> create(@NonNull
 @NonNull Function<? super T, ? extends CompletionStage<Boolean>> onNext,
 @NonNull
 @NonNull Function<? super Throwable, ? extends CompletionStage<Void>> onFinish)

Creates a StreamSink via lambda callbacks for next(Object) and finish(Throwable).

Non-fatal exceptions thrown by the callbacks are turned into failed CompletableFuture.failedFuture(Throwable)s.

Type Parameters:

T - the element type of the stream

Parameters:

onNext - the callback for the next method

onFinish - the callback for the finish method

Returns:

the new StreamSink instance