ActorContext.getParent for Java API #22413

akka-docs/rst/java/code/jdocs/stream/javadsl/cookbook/RecipeDroppyBroadcast.java

@@ -0,0 +1,77 @@
+/**
+ *  Copyright (C) 2015-2017 Lightbend Inc. <http://www.lightbend.com/>
+ */
+package jdocs.stream.javadsl.cookbook;
+
+import akka.Done;
+import akka.NotUsed;
+import akka.actor.ActorSystem;
+import akka.stream.*;
+import akka.stream.javadsl.*;
+import akka.testkit.JavaTestKit;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CompletionStage;
+
+public class RecipeDroppyBroadcast extends RecipeTest {
+  static ActorSystem system;
+  static Materializer mat;
+
+  @BeforeClass
+  public static void setup() {
+    system = ActorSystem.create("RecipeDroppyBroadcast");
+    mat = ActorMaterializer.create(system);
+  }
+
+  @AfterClass
+  public static void tearDown() {
+    JavaTestKit.shutdownActorSystem(system);
+    system = null;
+    mat = null;
+  }
+
+  @Test
+  public void work() throws Exception {
+    new JavaTestKit(system) {
+      //#droppy-bcast
+      // Makes a sink drop elements if too slow
+      public <T> Sink<T, CompletionStage<Done>> droppySink(Sink<T, CompletionStage<Done>> sink, int size) {
+        return Flow.<T> create()
+          .buffer(size, OverflowStrategy.dropHead())
+          .toMat(sink, Keep.right());
+      }
+      //#droppy-bcast
+
+      {
+        final List<Integer> nums = new ArrayList<>();
+        for (int i = 0; i < 100; i++) {
+          nums.add(i + 1);
+        }
+
+        final Sink<Integer, CompletionStage<Done>> mySink1 = Sink.ignore();
+        final Sink<Integer, CompletionStage<Done>> mySink2 = Sink.ignore();
+        final Sink<Integer, CompletionStage<Done>> mySink3 = Sink.ignore();
+
+        final Source<Integer, NotUsed> myData = Source.from(nums);
+
+        //#droppy-bcast2
+        RunnableGraph.fromGraph(GraphDSL.create(builder -> {
+          final int outputCount = 3;
+          final UniformFanOutShape<Integer, Integer> bcast =
+            builder.add(Broadcast.create(outputCount));
+          builder.from(builder.add(myData)).toFanOut(bcast);
+          builder.from(bcast).to(builder.add(droppySink(mySink1, 10)));
+          builder.from(bcast).to(builder.add(droppySink(mySink2, 10)));
+          builder.from(bcast).to(builder.add(droppySink(mySink3, 10)));
+          return ClosedShape.getInstance();
+        }));
+        //#droppy-bcast2
+      }
+    };
+  }
+
+}