pekko/akka-docs/src/main/paradox/stream/operators/Source/fromJavaStream.md

fromJavaStream

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

@refSource operators

Signature

@apidocStreamConverters.fromJavaStream { scala="#fromJavaStreamT,S<: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 { #from-javaStream }

Java

@@snip From.java { #from-javaStream }

Reactive Streams semantics

@@@div { .callout }

emits the next value returned from the iterator

completes when the iterator reaches its end

@@@