java.lang.Object
- akka.stream.scaladsl.Source<Out,Mat>

All Implemented Interfaces:

Graph<SourceShape<Out>,Mat>, FlowOps<Out,Mat>, FlowOpsMat<Out,Mat>
```
public final class Source<Out,Mat>
extends java.lang.Object
implements FlowOpsMat<Out,Mat>, Graph<SourceShape<Out>,Mat>
```
Connect this Source to a Sink, concatenating the processing steps of both.

Constructor Summary

Constructors
Constructor Description

Source(LinearTraversalBuilder traversalBuilder, SourceShape<Out> shape)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static <T> Source<T,ActorRef>`	`actorPublisher(Props props)`	Deprecated. Use `akka.stream.stage.GraphStage` and `fromGraph` instead, it allows for all operations an Actor would and is more type-safe as well as guaranteed to be ReactiveStreams compliant.
`static <T> Source<T,ActorRef>`	`actorRef(int bufferSize, OverflowStrategy overflowStrategy)`	Creates a `Source` that is materialized as an `ActorRef`.
`static <T> Source<T,ActorRef>`	`actorRef(scala.PartialFunction<java.lang.Object,CompletionStrategy> completionMatcher, scala.PartialFunction<java.lang.Object,java.lang.Throwable> failureMatcher, int bufferSize, OverflowStrategy overflowStrategy)`	INTERNAL API
`static <T> Source<T,ActorRef>`	`actorRefWithAck(java.lang.Object ackMessage)`	Creates a `Source` that is materialized as an `ActorRef`.
`static <T> Source<T,ActorRef>`	`actorRefWithAck(scala.Option<ActorRef> ackTo, java.lang.Object ackMessage, scala.PartialFunction<java.lang.Object,CompletionStrategy> completionMatcher, scala.PartialFunction<java.lang.Object,java.lang.Throwable> failureMatcher)`	INTERNAL API
`Source<Out,Mat>`	`addAttributes(Attributes attr)`	Add the given attributes to this Source.
`static <T> Source<T,NotUsed>`	`apply(scala.collection.immutable.Iterable<T> iterable)`	Helper to create `Source` from `Iterable`.
`Source<Out,Mat>`	`asJava()`	Converts this Scala DSL element to it's Java DSL counterpart.
`<Ctx> SourceWithContext<Out,Ctx,Mat>`	`asSourceWithContext(scala.Function1<Out,Ctx> f)`	API MAY CHANGE
`static <T> Source<T,org.reactivestreams.Subscriber<T>>`	`asSubscriber()`	Creates a `Source` that is materialized as a `Subscriber`
`Source<Out,Mat>`	`async()`	Put an asynchronous boundary around this `Source`
`Source<Out,Mat>`	`async(java.lang.String dispatcher)`	Put an asynchronous boundary around this `Graph`
`Source<Out,Mat>`	`async(java.lang.String dispatcher, int inputBufferSize)`	Put an asynchronous boundary around this `Graph`
`<T,U> Source<U,NotUsed>`	`combine(Source<T,?> first, Source<T,?> second, scala.collection.Seq<Source<T,?>> rest, scala.Function1<java.lang.Object,Graph<UniformFanInShape<T,U>,NotUsed>> strategy)`	Deprecated. Use `Source.combine` on companion object instead.
`static <T,U,M1,M2,M> Source<U,M>`	`combineMat(Source<T,M1> first, Source<T,M2> second, scala.Function1<java.lang.Object,Graph<UniformFanInShape<T,U>,NotUsed>> strategy, scala.Function2<M1,M2,M> matF)`	Combines two sources with fan-in strategy like `Merge` or `Concat` and returns `Source` with a materialized value.
`static <T> Source<T,NotUsed>`	`cycle(scala.Function0<scala.collection.Iterator<T>> f)`	Creates `Source` that will continually produce given elements in specified order.
`static <T> Source<T,NotUsed>`	`empty()`	A `Source` with no elements, i.e.
`static <T> Source<T,NotUsed>`	`failed(java.lang.Throwable cause)`	Create a `Source` that immediately ends the stream with the `cause` error to every connected `Sink`.
`static <T> Source<T,NotUsed>`	`fromCompletionStage(java.util.concurrent.CompletionStage<T> future)`	Starts a new `Source` from the given `Future`.
`static <T> Source<T,NotUsed>`	`fromFuture(scala.concurrent.Future<T> future)`	Starts a new `Source` from the given `Future`.
`static <T,M> Source<T,scala.concurrent.Future<M>>`	`fromFutureSource(scala.concurrent.Future<Graph<SourceShape<T>,M>> future)`	Streams the elements of the given future source once it successfully completes.
`static <T,M> Source<T,M>`	`fromGraph(Graph<SourceShape<T>,M> g)`	A graph with the shape of a source logically is a source, this method makes it so also in type.
`static <T> Source<T,NotUsed>`	`fromIterator(scala.Function0<scala.collection.Iterator<T>> f)`	Helper to create `Source` from `Iterator`.
`static <T> Source<T,NotUsed>`	`fromPublisher(org.reactivestreams.Publisher<T> publisher)`	Helper to create `Source` from `Publisher`.
`static <T,M> Source<T,java.util.concurrent.CompletionStage<M>>`	`fromSourceCompletionStage(java.util.concurrent.CompletionStage<? extends Graph<SourceShape<T>,M>> completion)`	Streams the elements of an asynchronous source once its given `completion` operator completes.
`static <T,M> Source<T,scala.concurrent.Future<M>>`	`lazily(scala.Function0<Source<T,M>> create)`	Creates a `Source` that is not materialized until there is downstream demand, when the source gets materialized the materialized future is completed with its value, if downstream cancels or fails without any demand the create factory is never called and the materialized `Future` is failed.
`static <T> Source<T,scala.concurrent.Future<NotUsed>>`	`lazilyAsync(scala.Function0<scala.concurrent.Future<T>> create)`	Creates a `Source` from supplied future factory that is not called until downstream demand.
`<Mat2> Source<Out,Mat2>`	`mapMaterializedValue(scala.Function1<Mat,Mat2> f)`	Transform only the materialized value of this Source, leaving all other properties as they were.
`static <T> Source<T,scala.concurrent.Promise<scala.Option<T>>>`	`maybe()`	Create a `Source` which materializes a `Promise` which controls what element will be emitted by the Source.
`Source<Out,Mat>`	`named(java.lang.String name)`	Add a name attribute to this Source.
`scala.Tuple2<Mat,Source<Out,NotUsed>>`	`preMaterialize(Materializer materializer)`	Materializes this Source, immediately returning (1) its materialized value, and (2) a new Source that can be used to consume elements from the newly materialized Source.
`static <T> Source<T,SourceQueueWithComplete<T>>`	`queue(int bufferSize, OverflowStrategy overflowStrategy)`	Creates a `Source` that is materialized as an `SourceQueue`.
`static <T> Source<T,NotUsed>`	`repeat(T element)`	Create a `Source` that will continually emit the given element.
`<U> scala.concurrent.Future<U>`	`runFold(U zero, scala.Function2<U,Out,U> f, Materializer materializer)`	Shortcut for running this `Source` with a fold function.
`<U> scala.concurrent.Future<U>`	`runFoldAsync(U zero, scala.Function2<U,Out,scala.concurrent.Future<U>> f, Materializer materializer)`	Shortcut for running this `Source` with a foldAsync function.
`scala.concurrent.Future<Done>`	`runForeach(scala.Function1<Out,scala.runtime.BoxedUnit> f, Materializer materializer)`	Shortcut for running this `Source` with a foreach procedure.
`<U> scala.concurrent.Future<U>`	`runReduce(scala.Function2<U,U,U> f, Materializer materializer)`	Shortcut for running this `Source` with a reduce function.
`<Mat2> Mat2`	`runWith(Graph<SinkShape<Out>,Mat2> sink, Materializer materializer)`	Connect this `Source` to a `Sink` and run it.
`static <T,M> Source<T,scala.concurrent.Future<M>>`	`setup(scala.Function2<ActorMaterializer,Attributes,Source<T,M>> factory)`	Defers the creation of a `Source` until materialization.
`SourceShape<Out>`	`shape()`	The shape of a graph is all that is externally visible: its inlets and outlets.
`static <T> Source<T,NotUsed>`	`single(T element)`	Create a `Source` with one element.
`static <T> Source<T,Cancellable>`	`tick(scala.concurrent.duration.FiniteDuration initialDelay, scala.concurrent.duration.FiniteDuration interval, T tick)`	Elements are emitted periodically with the specified interval.
`<Mat2> RunnableGraph<Mat>`	`to(Graph<SinkShape<Out>,Mat2> sink)`	Connect this `Source` to a `Sink`, concatenating the processing steps of both.
`<Mat2,Mat3> RunnableGraph<Mat3>`	`toMat(Graph<SinkShape<Out>,Mat2> sink, scala.Function2<Mat,Mat2,Mat3> combine)`	Connect this `Source` to a `Sink`, concatenating the processing steps of both.
`java.lang.String`	`toString()`
`LinearTraversalBuilder`	`traversalBuilder()`	INTERNAL API.
`static <S,E> Source<E,NotUsed>`	`unfold(S s, scala.Function1<S,scala.Option<scala.Tuple2<S,E>>> f)`	Create a `Source` that will unfold a value of type `S` into a pair of the next state `S` and output elements of type `E`.
`static <S,E> Source<E,NotUsed>`	`unfoldAsync(S s, scala.Function1<S,scala.concurrent.Future<scala.Option<scala.Tuple2<S,E>>>> f)`	Same as `<S,E>unfold(S,scala.Function1<S,scala.Option<scala.Tuple2<S,E>>>)`, but uses an async function to generate the next state-element tuple.
`static <T,S> Source<T,NotUsed>`	`unfoldResource(scala.Function0<S> create, scala.Function1<S,scala.Option<T>> read, scala.Function1<S,scala.runtime.BoxedUnit> close)`	Start a new `Source` from some resource which can be opened, read and closed.
`static <T,S> Source<T,NotUsed>`	`unfoldResourceAsync(scala.Function0<scala.concurrent.Future<S>> create, scala.Function1<S,scala.concurrent.Future<scala.Option<T>>> read, scala.Function1<S,scala.concurrent.Future<Done>> close)`	Start a new `Source` from some resource which can be opened, read and closed.
`<T,Mat2> Source<T,Mat>`	`via(Graph<FlowShape<Out,T>,Mat2> flow)`
`<T,Mat2,Mat3> Source<T,Mat3>`	`viaMat(Graph<FlowShape<Out,T>,Mat2> flow, scala.Function2<Mat,Mat2,Mat3> combine)`	Transform this `Flow` by appending the given processing steps.
`Source<Out,Mat>`	`withAttributes(Attributes attr)`	Replace the attributes of this `Source` with the given ones.
`static <T> Source<scala.collection.immutable.Seq<T>,NotUsed>`	`zipN(scala.collection.immutable.Seq<Source<T,?>> sources)`	Combine the elements of multiple streams into a stream of sequences.
`static <T,O> Source<O,NotUsed>`	`zipWithN(scala.Function1<scala.collection.immutable.Seq<T>,O> zipper, scala.collection.immutable.Seq<Source<T,?>> sources)`

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

Methods inherited from interface akka.stream.scaladsl.FlowOps
$plus$plus, alsoTo, alsoToGraph, ask, ask, backpressureTimeout, batch, batchWeighted, buffer, collect, collectType, completionTimeout, concat, concatGraph, conflate, conflateWithSeed, delay, delay$default$2, detach, divertTo, divertToGraph, drop, dropWhile, dropWithin, expand, extrapolate, extrapolate$default$2, filter, filterNot, flatMapConcat, flatMapMerge, fold, foldAsync, groupBy, groupBy, grouped, groupedWeightedWithin, groupedWithin, idleTimeout, initialDelay, initialTimeout, interleave, interleave, interleaveGraph, interleaveGraph$default$3, intersperse, intersperse, keepAlive, limit, limitWeighted, log, log$default$2, log$default$3, map, mapAsync, mapAsyncUnordered, mapConcat, mapError, merge, merge$default$2, mergeGraph, mergeSorted, mergeSortedGraph, orElse, orElseGraph, prefixAndTail, prepend, prependGraph, recover, recoverWith, recoverWithRetries, reduce, scan, scanAsync, sliding, sliding$default$2, splitAfter, splitAfter, splitWhen, splitWhen, statefulMapConcat, take, takeWhile, takeWhile, takeWithin, throttle, throttle, throttle, throttle, throttleEven, throttleEven, watch, wireTap, wireTap, wireTapGraph, zip, zipGraph, zipLatest, zipLatestGraph, zipLatestWith, zipLatestWithGraph, zipWith, zipWithGraph, zipWithIndex

Methods inherited from interface akka.stream.scaladsl.FlowOpsMat
alsoToMat, concatMat, divertToMat, interleaveMat, interleaveMat, mergeMat, mergeMat$default$2, mergeSortedMat, monitor, monitor, monitorMat, orElseMat, prependMat, watchTermination, wireTapMat, zipLatestMat, zipLatestWithMat, zipMat, zipWithMat

- Constructor Detail
 - Source
```
public Source(LinearTraversalBuilder traversalBuilder,
 SourceShape<Out> shape)
```
- Method Detail
 - fromPublisher
```
public static <T> Source<T,NotUsed> fromPublisher(org.reactivestreams.Publisher<T> publisher)
```
 Helper to create Source from Publisher.
 Construct a transformation starting with given publisher. The transformation steps are executed by a series of Processor instances that mediate the flow of elements downstream and the propagation of back-pressure upstream.
 
 Parameters:
 
 publisher - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromIterator
```
public static <T> Source<T,NotUsed> fromIterator(scala.Function0<scala.collection.Iterator<T>> f)
```
 Helper to create Source from Iterator. Example usage: Source.fromIterator(() => Iterator.from(0))
 Start a new Source from the given function that produces anIterator. The produced stream of elements will continue until the iterator runs empty or fails during evaluation of the next() method. Elements are pulled out of the iterator in accordance with the demand coming from the downstream transformation steps.
 
 Parameters:
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)
 - cycle
```
public static <T> Source<T,NotUsed> cycle(scala.Function0<scala.collection.Iterator<T>> f)
```
 Creates Source that will continually produce given elements in specified order.
 Starts a new 'cycled' Source from the given elements. The producer stream of elements will continue infinitely by repeating the sequence of elements provided by function parameter.
 
 Parameters:
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromGraph
```
public static <T,M> Source<T,M> fromGraph(Graph<SourceShape<T>,M> g)
```
 A graph with the shape of a source logically is a source, this method makes it so also in type.
 
 Parameters:
 
 g - (undocumented)
 
 Returns:
 
 (undocumented)
 - setup
```
public static <T,M> Source<T,scala.concurrent.Future<M>> setup(scala.Function2<ActorMaterializer,Attributes,Source<T,M>> factory)
```
 Defers the creation of a Source until materialization. The factory function exposes ActorMaterializer which is going to be used during materialization and Attributes of the Source returned by this method.
 
 Parameters:
 
 factory - (undocumented)
 
 Returns:
 
 (undocumented)
 - apply
```
public static <T> Source<T,NotUsed> apply(scala.collection.immutable.Iterable<T> iterable)
```
 Helper to create Source from Iterable. Example usage: Source(Seq(1,2,3))
 Starts a new Source from the given Iterable. This is like starting from an Iterator, but every Subscriber directly attached to the Publisher of this stream will see an individual flow of elements (always starting from the beginning) regardless of when they subscribed.
 
 Parameters:
 
 iterable - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromFuture
```
public static <T> Source<T,NotUsed> fromFuture(scala.concurrent.Future<T> future)
```
 Starts a new Source from the given Future. The stream will consist of one element when the Future is completed with a successful value, which may happen before or after materializing the Flow. The stream terminates with a failure if the Future is completed with a failure.
 
 Parameters:
 
 future - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromCompletionStage
```
public static <T> Source<T,NotUsed> fromCompletionStage(java.util.concurrent.CompletionStage<T> future)
```
 Starts a new Source from the given Future. The stream will consist of one element when the Future is completed with a successful value, which may happen before or after materializing the Flow. The stream terminates with a failure if the Future is completed with a failure.
 
 Parameters:
 
 future - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromFutureSource
```
public static <T,M> Source<T,scala.concurrent.Future<M>> fromFutureSource(scala.concurrent.Future<Graph<SourceShape<T>,M>> future)
```
 Streams the elements of the given future source once it successfully completes. If the Future fails the stream is failed with the exception from the future. If downstream cancels before the stream completes the materialized Future will be failed with a StreamDetachedException
 
 Parameters:
 
 future - (undocumented)
 
 Returns:
 
 (undocumented)
 - fromSourceCompletionStage
```
public static <T,M> Source<T,java.util.concurrent.CompletionStage<M>> fromSourceCompletionStage(java.util.concurrent.CompletionStage<? extends Graph<SourceShape<T>,M>> completion)
```
 Streams the elements of an asynchronous source once its given completion operator completes. If the CompletionStage fails the stream is failed with the exception from the future. If downstream cancels before the stream completes the materialized Future will be failed with a StreamDetachedException
 
 Parameters:
 
 completion - (undocumented)
 
 Returns:
 
 (undocumented)
 - tick
```
public static <T> Source<T,Cancellable> tick(scala.concurrent.duration.FiniteDuration initialDelay,
 scala.concurrent.duration.FiniteDuration interval,
 T tick)
```
 Elements are emitted periodically with the specified interval. The tick element will be delivered to downstream consumers that has requested any elements. If a consumer has not requested any elements at the point in time when the tick element is produced it will not receive that tick element later. It will receive new tick elements as soon as it has requested more elements.
 
 Parameters:
 
 initialDelay - (undocumented)
 
 interval - (undocumented)
 
 tick - (undocumented)
 
 Returns:
 
 (undocumented)
 - single
```
public static <T> Source<T,NotUsed> single(T element)
```
 Create a Source with one element. Every connected Sink of this stream will see an individual stream consisting of one element.
 
 Parameters:
 
 element - (undocumented)
 
 Returns:
 
 (undocumented)
 - repeat
```
public static <T> Source<T,NotUsed> repeat(T element)
```
 Create a Source that will continually emit the given element.
 
 Parameters:
 
 element - (undocumented)
 
 Returns:
 
 (undocumented)
 - unfold
```
public static <S,E> Source<E,NotUsed> unfold(S s,
 scala.Function1<S,scala.Option<scala.Tuple2<S,E>>> f)
```
 Create a Source that will unfold a value of type S into a pair of the next state S and output elements of type E.
 For example, all the Fibonacci numbers under 10M:
 
 Source.unfold(0 -> 1) { case (a, _) if a > 10000000 => None case (a, b) => Some((b -> (a + b)) -> a) }
 Parameters:
 
 s - (undocumented)
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)
 - unfoldAsync
```
public static <S,E> Source<E,NotUsed> unfoldAsync(S s,
 scala.Function1<S,scala.concurrent.Future<scala.Option<scala.Tuple2<S,E>>>> f)
```
 Same as <S,E>unfold(S,scala.Function1<S,scala.Option<scala.Tuple2<S,E>>>), but uses an async function to generate the next state-element tuple.
 async fibonacci example:
 
 Source.unfoldAsync(0 -> 1) { case (a, _) if a > 10000000 => Future.successful(None) case (a, b) => Future{ Thread.sleep(1000) Some((b -> (a + b)) -> a) } }
 Parameters:
 
 s - (undocumented)
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)
 - empty
```
public static <T> Source<T,NotUsed> empty()
```
 A Source with no elements, i.e. an empty stream that is completed immediately for every connected Sink.
 
 Returns:
 
 (undocumented)
 - maybe
```
public static <T> Source<T,scala.concurrent.Promise<scala.Option<T>>> maybe()
```
 Create a Source which materializes a Promise which controls what element will be emitted by the Source. If the materialized promise is completed with a Some, that value will be produced downstream, followed by completion. If the materialized promise is completed with a None, no value will be produced downstream and completion will be signalled immediately. If the materialized promise is completed with a failure, then the returned source will terminate with that error. If the downstream of this source cancels before the promise has been completed, then the promise will be completed with None.
 
 Returns:
 
 (undocumented)
 - failed
```
public static <T> Source<T,NotUsed> failed(java.lang.Throwable cause)
```
 Create a Source that immediately ends the stream with the cause error to every connected Sink.
 
 Parameters:
 
 cause - (undocumented)
 
 Returns:
 
 (undocumented)
 - lazily
```
public static <T,M> Source<T,scala.concurrent.Future<M>> lazily(scala.Function0<Source<T,M>> create)
```
 Creates a Source that is not materialized until there is downstream demand, when the source gets materialized the materialized future is completed with its value, if downstream cancels or fails without any demand the create factory is never called and the materialized Future is failed.
 
 Parameters:
 
 create - (undocumented)
 
 Returns:
 
 (undocumented)
 - lazilyAsync
```
public static <T> Source<T,scala.concurrent.Future<NotUsed>> lazilyAsync(scala.Function0<scala.concurrent.Future<T>> create)
```
 Creates a Source from supplied future factory that is not called until downstream demand. When source gets materialized the materialized future is completed with the value from the factory. If downstream cancels or fails without any demand the create factory is never called and the materialized Future is failed.
 
 Parameters:
 
 create - (undocumented)
 
 Returns:
 
 (undocumented)
 
 See Also:
 
 Source.lazily
 - asSubscriber
```
public static <T> Source<T,org.reactivestreams.Subscriber<T>> asSubscriber()
```
 Creates a Source that is materialized as a Subscriber
 
 Returns:
 
 (undocumented)
 - actorPublisher
```
public static <T> Source<T,ActorRef> actorPublisher(Props props)
```
 Deprecated.
 Use akka.stream.stage.GraphStage and fromGraph instead, it allows for all operations an Actor would and is more type-safe as well as guaranteed to be ReactiveStreams compliant.
 
 Creates a Source that is materialized to an ActorRef which points to an Actor created according to the passed in Props. Actor created by the props must be ActorPublisher.
 
 Parameters:
 
 props - (undocumented)
 
 Returns:
 
 (undocumented)
 - actorRef
```
public static <T> Source<T,ActorRef> actorRef(scala.PartialFunction<java.lang.Object,CompletionStrategy> completionMatcher,
 scala.PartialFunction<java.lang.Object,java.lang.Throwable> failureMatcher,
 int bufferSize,
 OverflowStrategy overflowStrategy)
```
 INTERNAL API
 Creates a Source that is materialized as an ActorRef. Messages sent to this actor will be emitted to the stream if there is demand from downstream, otherwise they will be buffered until request for demand is received.
 Depending on the defined OverflowStrategy it might drop elements if there is no space available in the buffer.
 The strategy akka.stream.OverflowStrategy.backpressure is not supported, and an IllegalArgument("Backpressure overflowStrategy not supported") will be thrown if it is passed as argument.
 The buffer can be disabled by using bufferSize of 0 and then received messages are dropped if there is no demand from downstream. When bufferSize is 0 the overflowStrategy does not matter. An async boundary is added after this Source; as such, it is never safe to assume the downstream will always generate demand.
 The stream can be completed successfully by sending the actor reference a message that is matched by completionMatcher in which case already buffered elements will be signaled before signaling completion.
 The stream can be completed with failure by sending a message that is matched by failureMatcher. The extracted Throwable will be used to fail the stream. In case the Actor is still draining its internal buffer (after having received a message matched by completionMatcher) before signaling completion and it receives a message matched by failureMatcher, the failure will be signaled downstream immediately (instead of the completion signal).
 Note that terminating the actor without first completing it, either with a success or a failure, will prevent the actor triggering downstream completion and the stream will continue to run even though the source actor is dead. Therefore you should **not** attempt to manually terminate the actor such as with a PoisonPill.
 The actor will be stopped when the stream is completed, failed or canceled from downstream, i.e. you can watch it to get notified when that happens.
 See also akka.stream.scaladsl.Source.queue.
 
 Parameters:
 
 bufferSize - The size of the buffer in element count
 
 overflowStrategy - Strategy that is used when incoming elements cannot fit inside the buffer
 
 completionMatcher - (undocumented)
 
 failureMatcher - (undocumented)
 
 Returns:
 
 (undocumented)
 - actorRef
```
public static <T> Source<T,ActorRef> actorRef(int bufferSize,
 OverflowStrategy overflowStrategy)
```
 Creates a Source that is materialized as an ActorRef. Messages sent to this actor will be emitted to the stream if there is demand from downstream, otherwise they will be buffered until request for demand is received.
 Depending on the defined OverflowStrategy it might drop elements if there is no space available in the buffer.
 The strategy akka.stream.OverflowStrategy.backpressure is not supported, and an IllegalArgument("Backpressure overflowStrategy not supported") will be thrown if it is passed as argument.
 The buffer can be disabled by using bufferSize of 0 and then received messages are dropped if there is no demand from downstream. When bufferSize is 0 the overflowStrategy does not matter. An async boundary is added after this Source; as such, it is never safe to assume the downstream will always generate demand.
 The stream can be completed successfully by sending the actor reference a Status.Success. If the content is akka.stream.CompletionStrategy.immediately the completion will be signaled immidiately, otherwise if the content is akka.stream.CompletionStrategy.draining (or anything else) already buffered elements will be signaled before siganling completion. Sending PoisonPill will signal completion immediately but this behavior is deprecated and scheduled to be removed.
 The stream can be completed with failure by sending a Status.Failure to the actor reference. In case the Actor is still draining its internal buffer (after having received a Status.Success) before signaling completion and it receives a Status.Failure, the failure will be signaled downstream immediately (instead of the completion signal).
 The actor will be stopped when the stream is completed, failed or canceled from downstream, i.e. you can watch it to get notified when that happens.
 See also akka.stream.scaladsl.Source.queue.
 
 Parameters:
 
 bufferSize - The size of the buffer in element count
 
 overflowStrategy - Strategy that is used when incoming elements cannot fit inside the buffer
 
 Returns:
 
 (undocumented)
 - actorRefWithAck
```
public static <T> Source<T,ActorRef> actorRefWithAck(scala.Option<ActorRef> ackTo,
 java.lang.Object ackMessage,
 scala.PartialFunction<java.lang.Object,CompletionStrategy> completionMatcher,
 scala.PartialFunction<java.lang.Object,java.lang.Throwable> failureMatcher)
```
 INTERNAL API
 
 Parameters:
 
 ackTo - (undocumented)
 
 ackMessage - (undocumented)
 
 completionMatcher - (undocumented)
 
 failureMatcher - (undocumented)
 
 Returns:
 
 (undocumented)
 - actorRefWithAck
```
public static <T> Source<T,ActorRef> actorRefWithAck(java.lang.Object ackMessage)
```
 Creates a Source that is materialized as an ActorRef. Messages sent to this actor will be emitted to the stream if there is demand from downstream, and a new message will only be accepted after the previous messages has been consumed and acknowledged back. The stream will complete with failure if a message is sent before the acknowledgement has been replied back.
 The stream can be completed successfully by sending the actor reference a Status.Success. If the content is akka.stream.CompletionStrategy.immediately the completion will be signaled immidiately, otherwise if the content is akka.stream.CompletionStrategy.draining (or anything else) already buffered element will be signaled before siganling completion.
 The stream can be completed with failure by sending a Status.Failure to the actor reference. In case the Actor is still draining its internal buffer (after having received a Status.Success) before signaling completion and it receives a Status.Failure, the failure will be signaled downstream immediately (instead of the completion signal).
 The actor will be stopped when the stream is completed, failed or canceled from downstream, i.e. you can watch it to get notified when that happens.
 
 Parameters:
 
 ackMessage - (undocumented)
 
 Returns:
 
 (undocumented)
 - combineMat
```
public static <T,U,M1,M2,M> Source<U,M> combineMat(Source<T,M1> first,
 Source<T,M2> second,
 scala.Function1<java.lang.Object,Graph<UniformFanInShape<T,U>,NotUsed>> strategy,
 scala.Function2<M1,M2,M> matF)
```
 Combines two sources with fan-in strategy like Merge or Concat and returns Source with a materialized value.
 
 Parameters:
 
 first - (undocumented)
 
 second - (undocumented)
 
 strategy - (undocumented)
 
 matF - (undocumented)
 
 Returns:
 
 (undocumented)
 - zipN
```
public static <T> Source<scala.collection.immutable.Seq<T>,NotUsed> zipN(scala.collection.immutable.Seq<Source<T,?>> sources)
```
 Combine the elements of multiple streams into a stream of sequences.
 
 Parameters:
 
 sources - (undocumented)
 
 Returns:
 
 (undocumented)
 - zipWithN
```
public static <T,O> Source<O,NotUsed> zipWithN(scala.Function1<scala.collection.immutable.Seq<T>,O> zipper,
 scala.collection.immutable.Seq<Source<T,?>> sources)
```
 - queue
```
public static <T> Source<T,SourceQueueWithComplete<T>> queue(int bufferSize,
 OverflowStrategy overflowStrategy)
```
 Creates a Source that is materialized as an SourceQueue. You can push elements to the queue and they will be emitted to the stream if there is demand from downstream, otherwise they will be buffered until request for demand is received. Elements in the buffer will be discarded if downstream is terminated.
 Depending on the defined OverflowStrategy it might drop elements if there is no space available in the buffer.
 Acknowledgement mechanism is available. akka.stream.scaladsl.SourceQueue.offer returns Future[QueueOfferResult] which completes with QueueOfferResult.Enqueued if element was added to buffer or sent downstream. It completes with QueueOfferResult.Dropped if element was dropped. Can also complete with QueueOfferResult.Failure - when stream failed or QueueOfferResult.QueueClosed when downstream is completed.
 The strategy akka.stream.OverflowStrategy.backpressure will not complete last offer():Future call when buffer is full.
 You can watch accessibility of stream with akka.stream.scaladsl.SourceQueue.watchCompletion. It returns future that completes with success when the operator is completed or fails when the stream is failed.
 The buffer can be disabled by using bufferSize of 0 and then received message will wait for downstream demand unless there is another message waiting for downstream demand, in that case offer result will be completed according to the overflow strategy.
 
 Parameters:
 
 bufferSize - size of buffer in element count
 
 overflowStrategy - Strategy that is used when incoming elements cannot fit inside the buffer
 
 Returns:
 
 (undocumented)
 - unfoldResource
```
public static <T,S> Source<T,NotUsed> unfoldResource(scala.Function0<S> create,
 scala.Function1<S,scala.Option<T>> read,
 scala.Function1<S,scala.runtime.BoxedUnit> close)
```
 Start a new Source from some resource which can be opened, read and closed. Interaction with resource happens in a blocking way.
 Example:
 Source.unfoldResource( () => new BufferedReader(new FileReader("...")), reader => Option(reader.readLine()), reader => reader.close())
 
 You can use the supervision strategy to handle exceptions for read function. All exceptions thrown by create or close will fail the stream.
 Restart supervision strategy will close and create blocking IO again. Default strategy is Stop which means that stream will be terminated on error in read function by default.
 You can configure the default dispatcher for this Source by changing the akka.stream.materializer.blocking-io-dispatcher or set it for a given Source by using ActorAttributes.
 Adheres to the ActorAttributes.SupervisionStrategy attribute.
 Parameters:
 
 create - - function that is called on stream start and creates/opens resource.
 
 read - - function that reads data from opened resource. It is called each time backpressure signal is received. Stream calls close and completes when read returns None.
 
 close - - function that closes resource
 
 Returns:
 
 (undocumented)
 - unfoldResourceAsync
```
public static <T,S> Source<T,NotUsed> unfoldResourceAsync(scala.Function0<scala.concurrent.Future<S>> create,
 scala.Function1<S,scala.concurrent.Future<scala.Option<T>>> read,
 scala.Function1<S,scala.concurrent.Future<Done>> close)
```
 Start a new Source from some resource which can be opened, read and closed. It's similar to unfoldResource but takes functions that return Futures instead of plain values.
 You can use the supervision strategy to handle exceptions for read function or failures of produced Futures. All exceptions thrown by create or close as well as fails of returned futures will fail the stream.
 Restart supervision strategy will close and create resource. Default strategy is Stop which means that stream will be terminated on error in read function (or future) by default.
 You can configure the default dispatcher for this Source by changing the akka.stream.materializer.blocking-io-dispatcher or set it for a given Source by using ActorAttributes.
 Adheres to the ActorAttributes.SupervisionStrategy attribute.
 
 Parameters:
 
 create - - function that is called on stream start and creates/opens resource.
 
 read - - function that reads data from opened resource. It is called each time backpressure signal is received. Stream calls close and completes when Future from read function returns None.
 
 close - - function that closes resource
 
 Returns:
 
 (undocumented)
 - traversalBuilder
```
public 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<Out,Mat>
 
 Returns:
 
 (undocumented)
 - shape
```
public SourceShape<Out> 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<Out,Mat>
 
 Returns:
 
 (undocumented)
 - toString
```
public java.lang.String toString()
```
 Overrides:
 
 toString in class java.lang.Object
 - via
```
public <T,Mat2> Source<T,Mat> via(Graph<FlowShape<Out,T>,Mat2> flow)
```
 Specified by:
 
 via in interface FlowOps<Out,Mat>
 - viaMat
```
public <T,Mat2,Mat3> Source<T,Mat3> viaMat(Graph<FlowShape<Out,T>,Mat2> flow,
 scala.Function2<Mat,Mat2,Mat3> combine)
```
 Description copied from interface: FlowOpsMat
 Transform this Flow by appending the given processing steps.
 +---------------------------------+ | Resulting Flow[In, T, M2] | | | | +------+ +------+ | | | | | | | In ~~> | this | ~~Out~~> | flow | ~~> T | | Mat| | M| | | +------+ +------+ | +---------------------------------+
 The combine function is used to compose the materialized values of this flow and that flow into the materialized value of the resulting Flow.
 It is recommended to use the internally optimized Keep.left and Keep.right combiners where appropriate instead of manually writing functions that pass through one of the values.
 Specified by:
 
 viaMat in interface FlowOpsMat<Out,Mat>
 
 Parameters:
 
 flow - (undocumented)
 
 combine - (undocumented)
 
 Returns:
 
 (undocumented)
 - to
```
public <Mat2> RunnableGraph<Mat> to(Graph<SinkShape<Out>,Mat2> sink)
```
 Connect this Source to a Sink, concatenating the processing steps of both.
 
 Specified by:
 
 to in interface FlowOps<Out,Mat>
 
 Parameters:
 
 sink - (undocumented)
 
 Returns:
 
 (undocumented)
 - toMat
```
public <Mat2,Mat3> RunnableGraph<Mat3> toMat(Graph<SinkShape<Out>,Mat2> sink,
 scala.Function2<Mat,Mat2,Mat3> combine)
```
 Connect this Source to a Sink, concatenating the processing steps of both.
 
 Specified by:
 
 toMat in interface FlowOpsMat<Out,Mat>
 
 Parameters:
 
 sink - (undocumented)
 
 combine - (undocumented)
 
 Returns:
 
 (undocumented)
 - mapMaterializedValue
```
public <Mat2> Source<Out,Mat2> mapMaterializedValue(scala.Function1<Mat,Mat2> f)
```
 Transform only the materialized value of this Source, leaving all other properties as they were.
 
 Specified by:
 
 mapMaterializedValue in interface FlowOpsMat<Out,Mat>
 
 Parameters:
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)
 - preMaterialize
```
public scala.Tuple2<Mat,Source<Out,NotUsed>> preMaterialize(Materializer materializer)
```
 Materializes this Source, immediately returning (1) its materialized value, and (2) a new Source that can be used to consume elements from the newly materialized Source.
 
 Parameters:
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - runWith
```
public <Mat2> Mat2 runWith(Graph<SinkShape<Out>,Mat2> sink,
 Materializer materializer)
```
 Connect this Source to a Sink and run it. The returned value is the materialized value of the Sink, e.g. the Publisher of a akka.stream.scaladsl.Sink#publisher.
 
 Parameters:
 
 sink - (undocumented)
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - runFold
```
public  scala.concurrent.Future runFold(U zero,
 scala.Function2<U,Out,U> f,
 Materializer materializer)
```
 Shortcut for running this Source with a fold function. The given function is invoked 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.
 
 Parameters:
 
 zero - (undocumented)
 
 f - (undocumented)
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - runFoldAsync
```
public  scala.concurrent.Future runFoldAsync(U zero,
 scala.Function2<U,Out,scala.concurrent.Future> f,
 Materializer materializer)
```
 Shortcut for running this Source with a foldAsync function. The given function is invoked 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.
 
 Parameters:
 
 zero - (undocumented)
 
 f - (undocumented)
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - runReduce
```
public  scala.concurrent.Future runReduce(scala.Function2<U,U,U> f,
 Materializer materializer)
```
 Shortcut for running this Source with a reduce function. The given function is invoked 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.
 
 Parameters:
 
 f - (undocumented)
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - runForeach
```
public scala.concurrent.Future<Done> runForeach(scala.Function1<Out,scala.runtime.BoxedUnit> f,
 Materializer materializer)
```
 Shortcut for running this Source with a foreach procedure. The given procedure is invoked for each received element. The returned Future 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.
 
 Parameters:
 
 f - (undocumented)
 
 materializer - (undocumented)
 
 Returns:
 
 (undocumented)
 - withAttributes
```
public Source<Out,Mat> withAttributes(Attributes attr)
```
 Replace the attributes of this Source with the given ones. If this Source 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 FlowOps<Out,Mat>
 
 Specified by:
 
 withAttributes in interface Graph<Out,Mat>
 
 Parameters:
 
 attr - (undocumented)
 
 Returns:
 
 (undocumented)
 - addAttributes
```
public Source<Out,Mat> addAttributes(Attributes attr)
```
 Add the given attributes to this Source. If the specific attribute was already on this source it will replace the previous value. If this Source is a composite of multiple graphs, the added attributes will be on the composite and therefore less specific than attributes set directly on the individual graphs of the composite.
 
 Specified by:
 
 addAttributes in interface FlowOps<Out,Mat>
 
 Specified by:
 
 addAttributes in interface Graph<Out,Mat>
 
 Parameters:
 
 attr - (undocumented)
 
 Returns:
 
 (undocumented)
 - named
```
public Source<Out,Mat> named(java.lang.String name)
```
 Add a name attribute to this Source.
 
 Specified by:
 
 named in interface FlowOps<Out,Mat>
 
 Specified by:
 
 named in interface Graph<Out,Mat>
 
 Parameters:
 
 name - (undocumented)
 
 Returns:
 
 (undocumented)
 - async
```
public Source<Out,Mat> async()
```
 Put an asynchronous boundary around this Source
 
 Specified by:
 
 async in interface FlowOps<Out,Mat>
 
 Specified by:
 
 async in interface Graph<Out,Mat>
 
 Returns:
 
 (undocumented)
 - async
```
public Source<Out,Mat> async(java.lang.String dispatcher)
```
 Put an asynchronous boundary around this Graph
 
 Specified by:
 
 async in interface Graph<Out,Mat>
 
 Parameters:
 
 dispatcher - Run the graph on this dispatcher
 
 Returns:
 
 (undocumented)
 - async
```
public Source<Out,Mat> async(java.lang.String dispatcher,
 int inputBufferSize)
```
 Put an asynchronous boundary around this Graph
 
 Specified by:
 
 async in interface Graph<Out,Mat>
 
 Parameters:
 
 dispatcher - Run the graph on this dispatcher
 
 inputBufferSize - Set the input buffer to this size for the graph
 
 Returns:
 
 (undocumented)
 - asJava
```
public Source<Out,Mat> asJava()
```
 Converts this Scala DSL element to it's Java DSL counterpart.
 
 Returns:
 
 (undocumented)
 - combine
```
public <T,U> Source<U,NotUsed> combine(Source<T,?> first,
 Source<T,?> second,
 scala.collection.Seq<Source<T,?>> rest,
 scala.Function1<java.lang.Object,Graph<UniformFanInShape<T,U>,NotUsed>> strategy)
```
 Deprecated.
 Use `Source.combine` on companion object instead. Since 2.5.5.
 
 Combines several sources with fan-in strategy like Merge or Concat and returns Source.
 
 Parameters:
 
 first - (undocumented)
 
 second - (undocumented)
 
 rest - (undocumented)
 
 strategy - (undocumented)
 
 Returns:
 
 (undocumented)
 - asSourceWithContext
```
public <Ctx> SourceWithContext<Out,Ctx,Mat> asSourceWithContext(scala.Function1<Out,Ctx> f)
```
 API MAY CHANGE
 
 Parameters:
 
 f - (undocumented)
 
 Returns:
 
 (undocumented)

Class Source<Out,​Mat>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface akka.stream.scaladsl.FlowOps

Methods inherited from interface akka.stream.scaladsl.FlowOpsMat

Constructor Detail

Source

Method Detail

fromPublisher

fromIterator

cycle

fromGraph

setup

apply

fromFuture

fromCompletionStage

fromFutureSource

fromSourceCompletionStage

tick

single

repeat

unfold

unfoldAsync

empty

maybe

failed

lazily

lazilyAsync

asSubscriber

actorPublisher

actorRef

actorRef

actorRefWithAck

actorRefWithAck

combineMat

zipN

zipWithN

queue

unfoldResource

unfoldResourceAsync

traversalBuilder

shape

toString

via

viaMat

to

toMat

mapMaterializedValue

preMaterialize

runWith

runFold

runFoldAsync

runReduce

runForeach

withAttributes

addAttributes

named

async

async

async

asJava

combine

asSourceWithContext

Class Source<Out,Mat>