// #simple-source public class NumbersSource extends GraphStage<SourceShape<Integer>> { // Define the (sole) output port of this stage public final Outlet<Integer> out = Outlet.create("NumbersSource.out"); // Define the shape of this stage, which is SourceShape with the port we defined above private final SourceShape<Integer> shape = SourceShape.of(out); @Override public SourceShape<Integer> shape() { return shape; } // This is where the actual (possibly stateful) logic is created @Override public GraphStageLogic createLogic(Attributes inheritedAttributes) { return new GraphStageLogic(shape()) { // All state MUST be inside the GraphStageLogic, // never inside the enclosing GraphStage. // This state is safe to access and modify from all the // callbacks that are provided by GraphStageLogic and the // registered handlers. private int counter = 1; { setHandler( out, new AbstractOutHandler() { @Override public void onPull() { push(out, counter); counter += 1; } }); } }; } }
public static void main(String[] args) { Outlet<Integer> outlet = null; Outlet<Integer> outlet1 = null; Outlet<Integer> outlet2 = null; Inlet<Integer> inlet = null; Inlet<Integer> inlet1 = null; Inlet<Integer> inlet2 = null; Flow<Integer, Integer, BoxedUnit> flow = Flow.of(Integer.class); Flow<Integer, Integer, BoxedUnit> flow1 = Flow.of(Integer.class); Flow<Integer, Integer, BoxedUnit> flow2 = Flow.of(Integer.class); Promise<Option<Integer>> promise = null; { Graph<SourceShape<Integer>, BoxedUnit> graphSource = null; Graph<SinkShape<Integer>, BoxedUnit> graphSink = null; Graph<FlowShape<Integer, Integer>, BoxedUnit> graphFlow = null; // #flow-wrap Source<Integer, BoxedUnit> source = Source.fromGraph(graphSource); Sink<Integer, BoxedUnit> sink = Sink.fromGraph(graphSink); Flow<Integer, Integer, BoxedUnit> aflow = Flow.fromGraph(graphFlow); Flow.fromSinkAndSource(Sink.<Integer>head(), Source.single(0)); Flow.fromSinkAndSourceMat(Sink.<Integer>head(), Source.single(0), Keep.left()); // #flow-wrap Graph<BidiShape<Integer, Integer, Integer, Integer>, BoxedUnit> bidiGraph = null; // #bidi-wrap BidiFlow<Integer, Integer, Integer, Integer, BoxedUnit> bidiFlow = BidiFlow.fromGraph(bidiGraph); BidiFlow.fromFlows(flow1, flow2); BidiFlow.fromFlowsMat(flow1, flow2, Keep.both()); // #bidi-wrap } { // #graph-create GraphDSL.create( builder -> { // ... return ClosedShape.getInstance(); }); GraphDSL.create( builder -> { // ... return new FlowShape<>(inlet, outlet); }); // #graph-create } { // #graph-create-2 GraphDSL.create( builder -> { // ... return SourceShape.of(outlet); }); GraphDSL.create( builder -> { // ... return SinkShape.of(inlet); }); GraphDSL.create( builder -> { // ... return FlowShape.of(inlet, outlet); }); GraphDSL.create( builder -> { // ... return BidiShape.of(inlet1, outlet1, inlet2, outlet2); }); // #graph-create-2 } { // #graph-builder GraphDSL.create( builder -> { builder.from(outlet).toInlet(inlet); builder.from(outlet).via(builder.add(flow)).toInlet(inlet); builder.from(builder.add(Source.single(0))).to(builder.add(Sink.head())); // ... return ClosedShape.getInstance(); }); // #graph-builder } // #source-creators Source<Integer, Promise<Option<Integer>>> src = Source.<Integer>maybe(); // Complete the promise with an empty option to emulate the old lazyEmpty promise.trySuccess(scala.Option.empty()); final Source<String, Cancellable> ticks = Source.tick( FiniteDuration.create(0, TimeUnit.MILLISECONDS), FiniteDuration.create(200, TimeUnit.MILLISECONDS), "tick"); final Source<Integer, BoxedUnit> pubSource = Source.fromPublisher(TestPublisher.<Integer>manualProbe(true, sys)); final Source<Integer, BoxedUnit> futSource = Source.fromFuture(Futures.successful(42)); final Source<Integer, Subscriber<Integer>> subSource = Source.<Integer>asSubscriber(); // #source-creators // #sink-creators final Sink<Integer, BoxedUnit> subSink = Sink.fromSubscriber(TestSubscriber.<Integer>manualProbe(sys)); // #sink-creators // #sink-as-publisher final Sink<Integer, Publisher<Integer>> pubSink = Sink.<Integer>asPublisher(false); final Sink<Integer, Publisher<Integer>> pubSinkFanout = Sink.<Integer>asPublisher(true); // #sink-as-publisher // #empty-flow Flow<Integer, Integer, BoxedUnit> emptyFlow = Flow.<Integer>create(); // or Flow<Integer, Integer, BoxedUnit> emptyFlow2 = Flow.of(Integer.class); // #empty-flow // #flatMapConcat Flow.<Source<Integer, BoxedUnit>>create() .<Integer, BoxedUnit>flatMapConcat( new Function<Source<Integer, BoxedUnit>, Source<Integer, BoxedUnit>>() { @Override public Source<Integer, BoxedUnit> apply(Source<Integer, BoxedUnit> param) throws Exception { return param; } }); // #flatMapConcat Uri uri = null; // #raw-query final akka.japi.Option<String> theRawQueryString = uri.rawQueryString(); // #raw-query // #query-param final akka.japi.Option<String> aQueryParam = uri.query().get("a"); // #query-param // #file-source-sink final Source<ByteString, Future<Long>> fileSrc = FileIO.fromFile(new File(".")); final Source<ByteString, Future<Long>> otherFileSrc = FileIO.fromFile(new File("."), 1024); final Sink<ByteString, Future<Long>> fileSink = FileIO.toFile(new File(".")); // #file-source-sink // #input-output-stream-source-sink final Source<ByteString, Future<java.lang.Long>> inputStreamSrc = StreamConverters.fromInputStream( new Creator<InputStream>() { public InputStream create() { return new SomeInputStream(); } }); final Source<ByteString, Future<java.lang.Long>> otherInputStreamSrc = StreamConverters.fromInputStream( new Creator<InputStream>() { public InputStream create() { return new SomeInputStream(); } }, 1024); final Sink<ByteString, Future<java.lang.Long>> outputStreamSink = StreamConverters.fromOutputStream( new Creator<OutputStream>() { public OutputStream create() { return new SomeOutputStream(); } }); // #input-output-stream-source-sink // #output-input-stream-source-sink final FiniteDuration timeout = FiniteDuration.Zero(); final Source<ByteString, OutputStream> outputStreamSrc = StreamConverters.asOutputStream(); final Source<ByteString, OutputStream> otherOutputStreamSrc = StreamConverters.asOutputStream(timeout); final Sink<ByteString, InputStream> someInputStreamSink = StreamConverters.asInputStream(); final Sink<ByteString, InputStream> someOtherInputStreamSink = StreamConverters.asInputStream(timeout); // #output-input-stream-source-sink }