# fromJavaStream

Stream the values from a Java 8 `Stream`, requesting the next value when there is demand.

@ref[Source operators](../index.md#source-operators)

## Signature

@apidoc[StreamConverters.fromJavaStream](StreamConverters$) { scala="#fromJavaStream[T,S<:java.util.stream.BaseStream[T,S]](stream:()=>java.util.stream.BaseStream[T,S]):akka.stream.scaladsl.Source[T,akka.NotUsed]" java="#fromJavaStream(akka.japi.function.Creator)" }


## Description

Stream the values from a Java 8 `Stream`, requesting the next value when there is demand. The iterator will be created anew
for each materialization, which is the reason the @scala[`method`] @java[`factory`] takes a @scala[`function`] @java[`Creator`] rather than an `Stream` directly.

You can use `Source.async` to create asynchronous boundaries between synchronous java stream and the rest of flow.

## Example
 
Scala
:   @@snip [From.scala](/akka-docs/src/test/scala/docs/stream/operators/source/From.scala) { #from-javaStream }

Java
:   @@snip [From.java](/akka-docs/src/test/java/jdocs/stream/operators/source/From.java) { #from-javaStream }


## Reactive Streams semantics

@@@div { .callout }

**emits** the next value returned from the iterator

**completes** when the iterator reaches its end

@@@