ActorContext.getParent for Java API #22413

akka-docs/rst/java/code/jdocs/io/JavaReadBackPressure.java

@@ -0,0 +1,97 @@
+package jdocs.io;
+
+import akka.actor.ActorRef;
+import akka.actor.Props;
+import akka.actor.AbstractActor;
+import akka.io.Inet;
+import akka.io.Tcp;
+import akka.io.TcpMessage;
+import akka.util.ByteString;
+
+import java.net.InetSocketAddress;
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Copyright (C) 2009-2017 Lightbend Inc. <http://www.lightbend.com>
+ */
+public class JavaReadBackPressure {
+
+    static public class Listener extends AbstractActor {
+        ActorRef tcp;
+        ActorRef listener;
+
+        @Override
+        //#pull-accepting
+        public Receive createReceive() {
+            return receiveBuilder()
+                .match(Tcp.Bound.class, x -> {
+                  listener = getSender();
+                  // Accept connections one by one
+                  listener.tell(TcpMessage.resumeAccepting(1), getSelf());
+                })
+                .match(Tcp.Connected.class, x -> {
+                  ActorRef handler = getContext().actorOf(Props.create(PullEcho.class, getSender()));
+                    getSender().tell(TcpMessage.register(handler), getSelf());
+                  // Resume accepting connections
+                  listener.tell(TcpMessage.resumeAccepting(1), getSelf());
+                })
+                .build();
+        }
+        //#pull-accepting
+
+        @Override
+        public void preStart() throws Exception {
+            //#pull-mode-bind
+            tcp = Tcp.get(getContext().getSystem()).manager();
+            final List<Inet.SocketOption> options = new ArrayList<Inet.SocketOption>();
+            tcp.tell(
+               TcpMessage.bind(self(), new InetSocketAddress("localhost", 0), 100, options, true),
+              getSelf()
+            );
+            //#pull-mode-bind
+        }
+
+        private void demonstrateConnect() {
+            //#pull-mode-connect
+            final List<Inet.SocketOption> options = new ArrayList<Inet.SocketOption>();
+            tcp.tell(
+               TcpMessage.connect(new InetSocketAddress("localhost", 3000), null, options, null, true),
+              getSelf()
+            );
+            //#pull-mode-connect
+        }
+    }
+
+    static public class Ack implements Tcp.Event {
+    }
+
+    static public class PullEcho extends AbstractActor {
+        final ActorRef connection;
+
+        public PullEcho(ActorRef connection) {
+            this.connection = connection;
+        }
+
+        //#pull-reading-echo
+        @Override
+        public void preStart() throws Exception {
+            connection.tell(TcpMessage.resumeReading(), getSelf());
+        }
+
+        @Override
+        public Receive createReceive() {
+            return receiveBuilder()
+                .match(Tcp.Received.class, message -> {
+                    ByteString data = message.data();
+                    connection.tell(TcpMessage.write(data, new Ack()), getSelf());
+                })
+                .match(Ack.class, message -> {
+                    connection.tell(TcpMessage.resumeReading(), getSelf());
+                })
+                .build();
+        }
+        //#pull-reading-echo
+    }
+
+}