ActorContext.getParent for Java API #22413

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

@@ -0,0 +1,79 @@
+/**
+ *  Copyright (C) 2015-2017 Lightbend Inc. <http://www.lightbend.com/>
+ */
+package jdocs.stream.javadsl.cookbook;
+
+import akka.NotUsed;
+import akka.actor.ActorSystem;
+import akka.japi.Pair;
+import akka.stream.ActorMaterializer;
+import akka.stream.Materializer;
+import akka.stream.javadsl.Flow;
+import akka.stream.testkit.TestPublisher;
+import akka.stream.testkit.TestSubscriber;
+import akka.stream.testkit.javadsl.TestSink;
+import akka.stream.testkit.javadsl.TestSource;
+import akka.testkit.JavaTestKit;
+import akka.testkit.TestLatch;
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import scala.concurrent.Await;
+import scala.concurrent.duration.Duration;
+
+import java.util.concurrent.TimeUnit;
+
+public class RecipeSimpleDrop extends RecipeTest {
+  static ActorSystem system;
+  static Materializer mat;
+
+  @BeforeClass
+  public static void setup() {
+    system = ActorSystem.create("RecipeSimpleDrop");
+    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) {
+      {
+    	@SuppressWarnings("unused")
+        //#simple-drop
+        final Flow<Message, Message, NotUsed> droppyStream =
+          Flow.of(Message.class).conflate((lastMessage, newMessage) -> newMessage);
+        //#simple-drop
+    	final TestLatch latch = new TestLatch(2, system);
+        final Flow<Message, Message, NotUsed> realDroppyStream =
+                Flow.of(Message.class).conflate((lastMessage, newMessage) -> { latch.countDown(); return newMessage; });
+
+        final Pair<TestPublisher.Probe<Message>, TestSubscriber.Probe<Message>> pubSub = TestSource
+          .<Message> probe(system)
+          .via(realDroppyStream)
+          .toMat(TestSink.probe(system),
+            (pub, sub) -> new Pair<>(pub, sub))
+          .run(mat);
+        final TestPublisher.Probe<Message> pub = pubSub.first();
+        final TestSubscriber.Probe<Message> sub = pubSub.second();
+
+        pub.sendNext(new Message("1"));
+        pub.sendNext(new Message("2"));
+        pub.sendNext(new Message("3"));
+        
+        Await.ready(latch, Duration.create(1, TimeUnit.SECONDS));
+        
+        sub.requestNext(new Message("3"));
+
+        pub.sendComplete();
+        sub.request(1);
+        sub.expectComplete();
+      }
+    };
+  }
+}