java.lang.Object
- org.apache.pekko.stream.scaladsl.Sink<In,Mat>

All Implemented Interfaces:

Graph<SinkShape<In>,Mat>
```
public final class Sink<In,Mat>
extends java.lang.Object
implements Graph<SinkShape<In>,Mat>
```
A Sink is a set of stream processing steps that has one open input. Can be used as a Subscriber

Nested Class Summary
- Nested classes/interfaces inherited from interface org.apache.pekko.stream.Graph
  Graph.GraphMapMatVal<S extends Shape,M>

Constructor Summary

Constructors
Constructor Description

Sink(org.apache.pekko.stream.impl.LinearTraversalBuilder traversalBuilder, SinkShape<In> shape)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static <T> Sink<T,NotUsed>`	`actorRef(ActorRef ref, java.lang.Object onCompleteMessage)`	Deprecated. Use variant accepting both on complete and on failure message.
`static <T> Sink<T,NotUsed>`	`actorRef(ActorRef ref, java.lang.Object onCompleteMessage, scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)`	INTERNAL API
`static <T> Sink<T,NotUsed>`	`actorRefWithAck(ActorRef ref, java.lang.Object onInitMessage, java.lang.Object ackMessage, java.lang.Object onCompleteMessage, scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)`	Deprecated. Use actorRefWithBackpressure accepting completion and failure matchers instead.
`static <T> scala.Function1<java.lang.Throwable,java.lang.Object>`	`actorRefWithAck$default$5()`
`static <T> Sink<T,NotUsed>`	`actorRefWithBackpressure(ActorRef ref, java.lang.Object onInitMessage, java.lang.Object ackMessage, java.lang.Object onCompleteMessage, scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)`	Sends the elements of the stream to the given `ActorRef` that sends back back-pressure signal.
`static <T> Sink<T,NotUsed>`	`actorRefWithBackpressure(ActorRef ref, java.lang.Object onInitMessage, java.lang.Object onCompleteMessage, scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)`	Sends the elements of the stream to the given `ActorRef` that sends back back-pressure signal.
`Sink<In,Mat>`	`addAttributes(Attributes attr)`	Add the given attributes to this `Sink`.
`<JIn extends In> Sink<JIn,Mat>`	`asJava()`	Converts this Scala DSL element to it's Java DSL counterpart.
`static <T> Sink<T,org.reactivestreams.Publisher<T>>`	`asPublisher(boolean fanout)`	A `Sink` that materializes into a `Publisher`.
`Sink<In,Mat>`	`async()`	Put an asynchronous boundary around this `Source`
`Sink<In,Mat>`	`async(java.lang.String dispatcher)`	Put an asynchronous boundary around this `Graph`
`Sink<In,Mat>`	`async(java.lang.String dispatcher, int inputBufferSize)`	Put an asynchronous boundary around this `Graph`
`static <T> Sink<T,NotUsed>`	`cancelled()`	A `Sink` that immediately cancels its upstream after materialization.
`static <T,That> Sink<T,scala.concurrent.Future<That>>`	`collection(scala.collection.Factory<T,That> cbf)`	A `Sink` that keeps on collecting incoming elements until upstream terminates.
`static <T,U> Sink<T,NotUsed>`	`combine(Sink<U,?> first, Sink<U,?> second, scala.collection.immutable.Seq<Sink<U,?>> rest, scala.Function1<java.lang.Object,Graph<UniformFanOutShape<T,U>,NotUsed>> strategy)`	Combine several sinks with fan-out strategy like `Broadcast` or `Balance` and returns `Sink`.
`<In2> Sink<In2,Mat>`	`contramap(scala.Function1<In2,In> f)`	Transform this Sink by applying a function to each incoming upstream element before it is passed to the `Sink`
`static <U,T> Sink<T,scala.concurrent.Future<U>>`	`fold(U zero, scala.Function2<U,T,U> f)`	A `Sink` that will invoke the given function for every received element, giving it its previous output (or the given `zero` value) and the element as input.
`static <U,T> Sink<T,scala.concurrent.Future<U>>`	`foldAsync(U zero, scala.Function2<U,T,scala.concurrent.Future<U>> f)`	A `Sink` that will invoke the given asynchronous function for every received element, giving it its previous output (or the given `zero` value) and the element as input.
`static <T> Sink<T,scala.concurrent.Future<Done>>`	`foreach(scala.Function1<T,scala.runtime.BoxedUnit> f)`	A `Sink` that will invoke the given procedure for each received element.
`static <T> Sink<T,scala.concurrent.Future<Done>>`	`foreachAsync(int parallelism, scala.Function1<T,scala.concurrent.Future<scala.runtime.BoxedUnit>> f)`	A `Sink` that will invoke the given procedure asynchronously for each received element.
`static <T> Sink<T,scala.concurrent.Future<Done>>`	`foreachParallel(int parallelism, scala.Function1<T,scala.runtime.BoxedUnit> f, scala.concurrent.ExecutionContext ec)`	Deprecated. Use `foreachAsync` instead, it allows you to choose how to run the procedure, by calling some other API returning a Future or spawning a new Future.
`static <T,M> Sink<T,M>`	`fromGraph(Graph<SinkShape<T>,M> g)`	A graph with the shape of a sink logically is a sink, this method makes it so also in type.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`fromMaterializer(scala.Function2<Materializer,Attributes,Sink<T,M>> factory)`	Defers the creation of a `Sink` until materialization.
`static <T> Sink<T,NotUsed>`	`fromSubscriber(org.reactivestreams.Subscriber<T> subscriber)`	Helper to create `Sink` from `Subscriber`.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`futureSink(scala.concurrent.Future<Sink<T,M>> future)`	Turn a `Future[Sink]` into a Sink that will consume the values of the source when the future completes successfully.
`Attributes`	`getAttributes()`
`static <T> Sink<T,scala.concurrent.Future<T>>`	`head()`	A `Sink` that materializes into a `Future` of the first value received.
`static <T> Sink<T,scala.concurrent.Future<scala.Option<T>>>`	`headOption()`	A `Sink` that materializes into a `Future` of the optional first value received.
`static Sink<java.lang.Object,scala.concurrent.Future<Done>>`	`ignore()`	A `Sink` that will consume the stream and discard the elements.
`static <T> Sink<T,scala.concurrent.Future<T>>`	`last()`	A `Sink` that materializes into a `Future` of the last value received.
`static <T> Sink<T,scala.concurrent.Future<scala.Option<T>>>`	`lastOption()`	A `Sink` that materializes into a `Future` of the optional last value received.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`lazyFutureSink(scala.Function0<scala.concurrent.Future<Sink<T,M>>> create)`	Defers invoking the `create` function to create a future sink until there is a first element passed from upstream.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`lazyInit(scala.Function1<T,scala.concurrent.Future<Sink<T,M>>> sinkFactory, scala.Function0<M> fallback)`	Deprecated. Use 'Sink.lazyFutureSink' in combination with 'Flow.prefixAndTail(1)' instead.
`static <T,M> Sink<T,scala.concurrent.Future<scala.Option<M>>>`	`lazyInitAsync(scala.Function0<scala.concurrent.Future<Sink<T,M>>> sinkFactory)`	Deprecated. Use 'Sink.lazyFutureSink' instead.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`lazySink(scala.Function0<Sink<T,M>> create)`	Defers invoking the `create` function to create a sink until there is a first element passed from upstream.
`<Mat2> Sink<In,Mat2>`	`mapMaterializedValue(scala.Function1<Mat,Mat2> f)`	Transform only the materialized value of this Sink, leaving all other properties as they were.
`Sink<In,Mat>`	`named(java.lang.String name)`	Add a name attribute to this Sink.
`static Sink<java.lang.Object,scala.concurrent.Future<Done>>`	`never()`	A `Sink` that will always backpressure never cancel and never consume any elements from the stream.
`static <T> Sink<T,NotUsed>`	`onComplete(scala.Function1<scala.util.Try<Done>,scala.runtime.BoxedUnit> callback)`	A `Sink` that when the flow is completed, either through a failure or normal completion, apply the provided function with `Success` or `Failure`.
`scala.Tuple2<Mat,Sink<In,NotUsed>>`	`preMaterialize(Materializer materializer)`	Materializes this Sink, immediately returning (1) its materialized value, and (2) a new Sink that can be consume elements 'into' the pre-materialized one.
`static <T> Sink<T,SinkQueueWithCancel<T>>`	`queue()`	Creates a `Sink` that is materialized as an `pekko.stream.scaladsl.SinkQueueWithCancel`.
`static <T> Sink<T,SinkQueueWithCancel<T>>`	`queue(int maxConcurrentPulls)`	Creates a `Sink` that is materialized as an `pekko.stream.scaladsl.SinkQueueWithCancel`.
`static <T> Sink<T,scala.concurrent.Future<T>>`	`reduce(scala.Function2<T,T,T> f)`	A `Sink` that will invoke the given function for every received element, giving it its previous output (from the second element) and the element as input.
`<Mat2> Mat2`	`runWith(Graph<SourceShape<In>,Mat2> source, Materializer materializer)`	Connect this `Sink` to a `Source` and run it.
`static <T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>>`	`seq()`	A `Sink` that keeps on collecting incoming elements until upstream terminates.
`static <T,M> Sink<T,scala.concurrent.Future<M>>`	`setup(scala.Function2<ActorMaterializer,Attributes,Sink<T,M>> factory)`	Deprecated. Use 'fromMaterializer' instead.
`SinkShape<In>`	`shape()`	The shape of a graph is all that is externally visible: its inlets and outlets.
`static <T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>>`	`takeLast(int n)`	A `Sink` that materializes into a a `Future` of `immutable.Seq[T]` containing the last `n` collected elements.
`java.lang.String`	`toString()`
`org.apache.pekko.stream.impl.LinearTraversalBuilder`	`traversalBuilder()`	INTERNAL API.
`Sink<In,Mat>`	`withAttributes(Attributes attr)`	Replace the attributes of this `Sink` with the given ones.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - Sink
```
public Sink(org.apache.pekko.stream.impl.LinearTraversalBuilder traversalBuilder,
            SinkShape<In> shape)
```
- Method Detail
  - fromGraph
```
public static <T,M> Sink<T,M> fromGraph(Graph<SinkShape<T>,M> g)
```
    A graph with the shape of a sink logically is a sink, this method makes it so also in type.
  - fromMaterializer
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> fromMaterializer(scala.Function2<Materializer,Attributes,Sink<T,M>> factory)
```
    Defers the creation of a Sink until materialization. The factory function exposes Materializer which is going to be used during materialization and Attributes of the Sink returned by this method.
  - setup
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> setup(scala.Function2<ActorMaterializer,Attributes,Sink<T,M>> factory)
```
    Deprecated.
    Use 'fromMaterializer' instead. Since Akka 2.6.0.
    
    Defers the creation of a Sink until materialization. The factory function exposes ActorMaterializer which is going to be used during materialization and Attributes of the Sink returned by this method.
  - fromSubscriber
```
public static <T> Sink<T,NotUsed> fromSubscriber(org.reactivestreams.Subscriber<T> subscriber)
```
    Helper to create Sink from Subscriber.
  - cancelled
```
public static <T> Sink<T,NotUsed> cancelled()
```
    A Sink that immediately cancels its upstream after materialization.
  - head
```
public static <T> Sink<T,scala.concurrent.Future<T>> head()
```
    A Sink that materializes into a Future of the first value received. If the stream completes before signaling at least a single element, the Future will be failed with a NoSuchElementException. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.
    See also <T>headOption().
  - headOption
```
public static <T> Sink<T,scala.concurrent.Future<scala.Option<T>>> headOption()
```
    A Sink that materializes into a Future of the optional first value received. If the stream completes before signaling at least a single element, the value of the Future will be None. If the stream signals an error errors before signaling at least a single element, the Future will be failed with the streams exception.
    See also <T>head().
  - last
```
public static <T> Sink<T,scala.concurrent.Future<T>> last()
```
    A Sink that materializes into a Future of the last value received. If the stream completes before signaling at least a single element, the Future will be failed with a NoSuchElementException. If the stream signals an error, the Future will be failed with the stream's exception.
    See also <T>lastOption(), <T>takeLast(int).
  - lastOption
```
public static <T> Sink<T,scala.concurrent.Future<scala.Option<T>>> lastOption()
```
    A Sink that materializes into a Future of the optional last value received. If the stream completes before signaling at least a single element, the value of the Future will be None. If the stream signals an error, the Future will be failed with the stream's exception.
    See also <T>last(), <T>takeLast(int).
  - takeLast
```
public static <T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>> takeLast(int n)
```
    A Sink that materializes into a a Future of immutable.Seq[T] containing the last n collected elements.
    If the stream completes before signaling at least n elements, the Future will complete with all elements seen so far. If the stream never completes, the Future will never complete. If there is a failure signaled in the stream the Future will be completed with failure.
  - seq
```
public static <T> Sink<T,scala.concurrent.Future<scala.collection.immutable.Seq<T>>> seq()
```
    A Sink that keeps on collecting incoming elements until upstream terminates. As upstream may be unbounded, Flow[T].take or the stricter Flow[T].limit (and their variants) may be used to ensure boundedness. Materializes into a Future of Seq[T] containing all the collected elements. Seq is limited to Int.MaxValue elements, this Sink will cancel the stream after having received that many elements.
    See also Flow.limit, Flow.limitWeighted, Flow.take, Flow.takeWithin, Flow.takeWhile
  - collection
```
public static <T,That> Sink<T,scala.concurrent.Future<That>> collection(scala.collection.Factory<T,That> cbf)
```
    A Sink that keeps on collecting incoming elements until upstream terminates. As upstream may be unbounded, Flow[T].take or the stricter Flow[T].limit (and their variants) may be used to ensure boundedness. Materializes into a Future of That[T] containing all the collected elements. That[T] is limited to the limitations of the CanBuildFrom associated with it. For example, Seq is limited to Int.MaxValue elements. See [The Architecture of Scala 2.13's Collections](https://docs.scala-lang.org/overviews/core/architecture-of-scala-213-collections.html) for more info. This Sink will cancel the stream after having received that many elements.
    See also Flow.limit, Flow.limitWeighted, Flow.take, Flow.takeWithin, Flow.takeWhile
  - asPublisher
```
public static <T> Sink<T,org.reactivestreams.Publisher<T>> asPublisher(boolean fanout)
```
    A Sink that materializes into a Publisher.
    If fanout is true, the materialized Publisher will support multiple Subscribers and the size of the inputBuffer configured for this operator becomes the maximum number of elements that the fastest Subscriber can be ahead of the slowest one before slowing the processing down due to back pressure.
    If fanout is false then the materialized Publisher will only support a single Subscriber and reject any additional Subscribers.
  - ignore
```
public static Sink<java.lang.Object,scala.concurrent.Future<Done>> ignore()
```
    A Sink that will consume the stream and discard the elements.
  - never
```
public static Sink<java.lang.Object,scala.concurrent.Future<Done>> never()
```
    A Sink that will always backpressure never cancel and never consume any elements from the stream.
  - foreach
```
public static <T> Sink<T,scala.concurrent.Future<Done>> foreach(scala.Function1<T,scala.runtime.BoxedUnit> f)
```
    A Sink that will invoke the given procedure for each received element. The sink is materialized into a Future which will be completed with Success when reaching the normal end of the stream, or completed with Failure if there is a failure signaled in the stream.
  - foreachAsync
```
public static <T> Sink<T,scala.concurrent.Future<Done>> foreachAsync(int parallelism,
                                                                           scala.Function1<T,scala.concurrent.Future<scala.runtime.BoxedUnit>> f)
```
    A Sink that will invoke the given procedure asynchronously for each received element. The sink is materialized into a Future which will be completed with Success when reaching the normal end of the stream, or completed with Failure if there is a failure signaled in the stream.
  - combine
```
public static <T,U> Sink<T,NotUsed> combine(Sink<U,?> first,
                                                        Sink<U,?> second,
                                                        scala.collection.immutable.Seq<Sink<U,?>> rest,
                                                        scala.Function1<java.lang.Object,Graph<UniformFanOutShape<T,U>,NotUsed>> strategy)
```
    Combine several sinks with fan-out strategy like Broadcast or Balance and returns Sink.
  - foreachParallel
```
public static <T> Sink<T,scala.concurrent.Future<Done>> foreachParallel(int parallelism,
                                                                              scala.Function1<T,scala.runtime.BoxedUnit> f,
                                                                              scala.concurrent.ExecutionContext ec)
```
    Deprecated.
    Use `foreachAsync` instead, it allows you to choose how to run the procedure, by calling some other API returning a Future or spawning a new Future. Since Akka 2.5.17.
    
    A Sink that will invoke the given function to each of the elements as they pass in. The sink is materialized into a Future
    If f throws an exception and the supervision decision is pekko.stream.Supervision.Stop the Future will be completed with failure.
    If f throws an exception and the supervision decision is pekko.stream.Supervision.Resume or pekko.stream.Supervision.Restart the element is dropped and the stream continues.
    See also Flow.mapAsyncUnordered
  - fold
```
public static <U,T> Sink<T,scala.concurrent.Future<U>> fold(U zero,
                                                                        scala.Function2<U,T,U> f)
```
    A Sink that will invoke the given function for every received element, giving it its previous output (or the given zero value) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.
    
    See Also:
    
    foldAsync(U, scala.Function2<U, T, scala.concurrent.Future<U>>)
  - foldAsync
```
public static <U,T> Sink<T,scala.concurrent.Future<U>> foldAsync(U zero,
                                                                             scala.Function2<U,T,scala.concurrent.Future<U>> f)
```
    A Sink that will invoke the given asynchronous function for every received element, giving it its previous output (or the given zero value) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.
    
    See Also:
    
    fold(U, scala.Function2<U, T, U>)
  - reduce
```
public static <T> Sink<T,scala.concurrent.Future<T>> reduce(scala.Function2<T,T,T> f)
```
    A Sink that will invoke the given function for every received element, giving it its previous output (from the second element) and the element as input. The returned Future will be completed with value of the final function evaluation when the input stream ends, or completed with Failure if there is a failure signaled in the stream.
    If the stream is empty (i.e. completes before signalling any elements), the reduce operator will fail its downstream with a NoSuchElementException, which is semantically in-line with that Scala's standard library collections do in such situations.
    Adheres to the ActorAttributes.SupervisionStrategy attribute.
  - onComplete
```
public static <T> Sink<T,NotUsed> onComplete(scala.Function1<scala.util.Try<Done>,scala.runtime.BoxedUnit> callback)
```
    A Sink that when the flow is completed, either through a failure or normal completion, apply the provided function with Success or Failure.
  - actorRef
```
public static <T> Sink<T,NotUsed> actorRef(ActorRef ref,
                                                 java.lang.Object onCompleteMessage,
                                                 scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)
```
    INTERNAL API
    Sends the elements of the stream to the given ActorRef. If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure the onFailureMessage will be invoked and its result will be sent to the destination actor.
    It will request at most maxInputBufferSize number of elements from upstream, but there is no back-pressure signal from the destination actor, i.e. if the actor is not consuming the messages fast enough the mailbox of the actor will grow. For potentially slow consumer actors it is recommended to use a bounded mailbox with zero mailbox-push-timeout-time or use a rate limiting operator in front of this Sink.
  - actorRef
```
public static <T> Sink<T,NotUsed> actorRef(ActorRef ref,
                                                 java.lang.Object onCompleteMessage)
```
    Deprecated.
    Use variant accepting both on complete and on failure message. Since Akka 2.6.0.
    
    Sends the elements of the stream to the given ActorRef. If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure a pekko.actor.Status.Failure message will be sent to the destination actor.
    It will request at most maxInputBufferSize number of elements from upstream, but there is no back-pressure signal from the destination actor, i.e. if the actor is not consuming the messages fast enough the mailbox of the actor will grow. For potentially slow consumer actors it is recommended to use a bounded mailbox with zero mailbox-push-timeout-time or use a rate limiting operator in front of this Sink.
  - actorRefWithBackpressure
```
public static <T> Sink<T,NotUsed> actorRefWithBackpressure(ActorRef ref,
                                                                 java.lang.Object onInitMessage,
                                                                 java.lang.Object ackMessage,
                                                                 java.lang.Object onCompleteMessage,
                                                                 scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)
```
    Sends the elements of the stream to the given ActorRef that sends back back-pressure signal. First element is always onInitMessage, then stream is waiting for acknowledgement message ackMessage from the given actor which means that it is ready to process elements. It also requires ackMessage message after each stream element to make backpressure work.
    If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure - result of onFailureMessage(throwable) function will be sent to the destination actor.
  - actorRefWithBackpressure
```
public static <T> Sink<T,NotUsed> actorRefWithBackpressure(ActorRef ref,
                                                                 java.lang.Object onInitMessage,
                                                                 java.lang.Object onCompleteMessage,
                                                                 scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)
```
    Sends the elements of the stream to the given ActorRef that sends back back-pressure signal. First element is always onInitMessage, then stream is waiting for acknowledgement message from the given actor which means that it is ready to process elements. It also requires an ack message after each stream element to make backpressure work. This variant will consider any message as ack message.
    If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure - result of onFailureMessage(throwable) function will be sent to the destination actor.
  - actorRefWithAck
```
public static <T> Sink<T,NotUsed> actorRefWithAck(ActorRef ref,
                                                        java.lang.Object onInitMessage,
                                                        java.lang.Object ackMessage,
                                                        java.lang.Object onCompleteMessage,
                                                        scala.Function1<java.lang.Throwable,java.lang.Object> onFailureMessage)
```
    Deprecated.
    Use actorRefWithBackpressure accepting completion and failure matchers instead. Since Akka 2.6.0.
    
    Sends the elements of the stream to the given ActorRef that sends back back-pressure signal. First element is always onInitMessage, then stream is waiting for acknowledgement message ackMessage from the given actor which means that it is ready to process elements. It also requires ackMessage message after each stream element to make backpressure work.
    If the target actor terminates the stream will be canceled. When the stream is completed successfully the given onCompleteMessage will be sent to the destination actor. When the stream is completed with failure - result of onFailureMessage(throwable) function will be sent to the destination actor.
  - actorRefWithAck$default$5
```
public static <T> scala.Function1<java.lang.Throwable,java.lang.Object> actorRefWithAck$default$5()
```
  - queue
```
public static <T> Sink<T,SinkQueueWithCancel<T>> queue(int maxConcurrentPulls)
```
    Creates a Sink that is materialized as an pekko.stream.scaladsl.SinkQueueWithCancel. pekko.stream.scaladsl.SinkQueueWithCancel.pull method is pulling element from the stream and returns Future[Option[T]. Future completes when element is available.
    Before calling pull method second time you need to ensure that number of pending pulls is less then maxConcurrentPulls or wait until some of the previous Futures completes. Pull returns Failed future with ''IllegalStateException'' if there will be more then maxConcurrentPulls number of pending pulls.
    Sink will request at most number of elements equal to size of inputBuffer from upstream and then stop back pressure. You can configure size of input buffer by using Sink.withAttributes method.
    For stream completion you need to pull all elements from pekko.stream.scaladsl.SinkQueueWithCancel including last None as completion marker
    See also pekko.stream.scaladsl.SinkQueueWithCancel
  - queue
```
public static <T> Sink<T,SinkQueueWithCancel<T>> queue()
```
    Creates a Sink that is materialized as an pekko.stream.scaladsl.SinkQueueWithCancel. pekko.stream.scaladsl.SinkQueueWithCancel.pull method is pulling element from the stream and returns Future[Option[T}. Future completes when element is available.
    Before calling pull method second time you need to wait until previous Future completes. Pull returns Failed future with ''IllegalStateException'' if previous future has not yet completed.
    Sink will request at most number of elements equal to size of inputBuffer from upstream and then stop back pressure. You can configure size of input buffer by using Sink.withAttributes method.
    For stream completion you need to pull all elements from pekko.stream.scaladsl.SinkQueueWithCancel including last None as completion marker
    See also pekko.stream.scaladsl.SinkQueueWithCancel
  - lazyInit
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> lazyInit(scala.Function1<T,scala.concurrent.Future<Sink<T,M>>> sinkFactory,
                                                                            scala.Function0<M> fallback)
```
    Deprecated.
    Use 'Sink.lazyFutureSink' in combination with 'Flow.prefixAndTail(1)' instead. Since Akka 2.6.0.
    
    Creates a real Sink upon receiving the first element. Internal Sink will not be created if there are no elements, because of completion or error.
    If upstream completes before an element was received then the Future is completed with the value created by fallback. If upstream fails before an element was received, sinkFactory throws an exception, or materialization of the internal sink fails then the Future is completed with the exception. Otherwise the Future is completed with the materialized value of the internal sink.
  - lazyInitAsync
```
public static <T,M> Sink<T,scala.concurrent.Future<scala.Option<M>>> lazyInitAsync(scala.Function0<scala.concurrent.Future<Sink<T,M>>> sinkFactory)
```
    Deprecated.
    Use 'Sink.lazyFutureSink' instead. Since Akka 2.6.0.
    
    Creates a real Sink upon receiving the first element. Internal Sink will not be created if there are no elements, because of completion or error.
    If upstream completes before an element was received then the Future is completed with None. If upstream fails before an element was received, sinkFactory throws an exception, or materialization of the internal sink fails then the Future is completed with the exception. Otherwise the Future is completed with the materialized value of the internal sink.
  - futureSink
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> futureSink(scala.concurrent.Future<Sink<T,M>> future)
```
    Turn a Future[Sink] into a Sink that will consume the values of the source when the future completes successfully. If the Future is completed with a failure the stream is failed.
    The materialized future value is completed with the materialized value of the future sink or failed with a NeverMaterializedException if upstream fails or downstream cancels before the future has completed.
  - lazySink
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> lazySink(scala.Function0<Sink<T,M>> create)
```
    Defers invoking the create function to create a sink until there is a first element passed from upstream.
    The materialized future value is completed with the materialized value of the created sink when that has successfully been materialized.
    If the create function throws or returns or the stream fails to materialize, in this case the materialized future value is failed with a pekko.stream.NeverMaterializedException.
  - lazyFutureSink
```
public static <T,M> Sink<T,scala.concurrent.Future<M>> lazyFutureSink(scala.Function0<scala.concurrent.Future<Sink<T,M>>> create)
```
    Defers invoking the create function to create a future sink until there is a first element passed from upstream.
    The materialized future value is completed with the materialized value of the created sink when that has successfully been materialized.
    If the create function throws or returns a future that is failed, or the stream fails to materialize, in this case the materialized future value is failed with a pekko.stream.NeverMaterializedException.
  - traversalBuilder
```
public org.apache.pekko.stream.impl.LinearTraversalBuilder traversalBuilder()
```
    Description copied from interface: Graph
    
    INTERNAL API.
    Every materializable element must be backed by a stream layout module
    
    Specified by:
    
    traversalBuilder in interface Graph<In,Mat>
  - shape
```
public SinkShape<In> shape()
```
    Description copied from interface: Graph
    
    The shape of a graph is all that is externally visible: its inlets and outlets.
    
    Specified by:
    
    shape in interface Graph<In,Mat>
  - toString
```
public java.lang.String toString()
```
    Overrides:
    
    toString in class java.lang.Object
  - contramap
```
public <In2> Sink<In2,Mat> contramap(scala.Function1<In2,In> f)
```
    Transform this Sink by applying a function to each *incoming* upstream element before it is passed to the Sink
    '''Backpressures when''' original Sink backpressures
    '''Cancels when''' original Sink cancels
  - runWith
```
public <Mat2> Mat2 runWith(Graph<SourceShape<In>,Mat2> source,
                           Materializer materializer)
```
    Connect this Sink to a Source and run it. The returned value is the materialized value of the Source, e.g. the Subscriber of a Source#subscriber.
    Note that the ActorSystem can be used as the implicit materializer parameter to use the pekko.stream.SystemMaterializer for running the stream.
  - mapMaterializedValue
```
public <Mat2> Sink<In,Mat2> mapMaterializedValue(scala.Function1<Mat,Mat2> f)
```
    Transform only the materialized value of this Sink, leaving all other properties as they were.
  - preMaterialize
```
public scala.Tuple2<Mat,Sink<In,NotUsed>> preMaterialize(Materializer materializer)
```
    Materializes this Sink, immediately returning (1) its materialized value, and (2) a new Sink that can be consume elements 'into' the pre-materialized one.
    Useful for when you need a materialized value of a Sink when handing it out to someone to materialize it for you.
  - withAttributes
```
public Sink<In,Mat> withAttributes(Attributes attr)
```
    Replace the attributes of this Sink with the given ones. If this Sink is a composite of multiple graphs, new attributes on the composite will be less specific than attributes set directly on the individual graphs of the composite.
    
    Specified by:
    
    withAttributes in interface Graph<In,Mat>
  - addAttributes
```
public Sink<In,Mat> addAttributes(Attributes attr)
```
    Add the given attributes to this Sink. If the specific attribute was already present on this graph this means the added attribute will be more specific than the existing one. If this Sink is a composite of multiple graphs, new attributes on the composite will be less specific than attributes set directly on the individual graphs of the composite.
    
    Specified by:
    
    addAttributes in interface Graph<In,Mat>
  - named
```
public Sink<In,Mat> named(java.lang.String name)
```
    Add a name attribute to this Sink.
    
    Specified by:
    
    named in interface Graph<In,Mat>
  - async
```
public Sink<In,Mat> async()
```
    Put an asynchronous boundary around this Source
    
    Specified by:
    
    async in interface Graph<In,Mat>
  - async
```
public Sink<In,Mat> async(java.lang.String dispatcher)
```
    Put an asynchronous boundary around this Graph
    
    Specified by:
    
    async in interface Graph<In,Mat>
    
    Parameters:
    
    dispatcher - Run the graph on this dispatcher
  - async
```
public Sink<In,Mat> async(java.lang.String dispatcher,
                                int inputBufferSize)
```
    Put an asynchronous boundary around this Graph
    
    Specified by:
    
    async in interface Graph<In,Mat>
    
    Parameters:
    
    dispatcher - Run the graph on this dispatcher
    
    inputBufferSize - Set the input buffer to this size for the graph
  - asJava
```
public <JIn extends In> Sink<JIn,Mat> asJava()
```
    Converts this Scala DSL element to it's Java DSL counterpart.
  - getAttributes
```
public Attributes getAttributes()
```
    Specified by:
    
    getAttributes in interface Graph<In,Mat>

Class Sink<In,​Mat>

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.pekko.stream.Graph

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

Sink

Method Detail

fromGraph

fromMaterializer

setup

fromSubscriber

cancelled

head

headOption

last

lastOption

takeLast

seq

collection

asPublisher

ignore

never

foreach

foreachAsync

combine

foreachParallel

fold

foldAsync

reduce

onComplete

actorRef

actorRef

actorRefWithBackpressure

actorRefWithBackpressure

actorRefWithAck

actorRefWithAck$default$5

queue

queue

lazyInit

lazyInitAsync

futureSink

lazySink

lazyFutureSink

traversalBuilder

shape

toString

contramap

runWith

mapMaterializedValue

preMaterialize

withAttributes

addAttributes

named

async

async

async

asJava

getAttributes

Class Sink<In,Mat>