Akka/Scala example source code file (HelloKernel.java)

This example Akka source code file (HelloKernel.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

actor, actorref, actorsystem, akka, bootable, hello, helloactor, hellokernel, kernel, string, untypedactor, worldactor

The HelloKernel.java Akka example source code

package sample.kernel.hello.java;

import akka.actor.ActorRef;
import akka.actor.UntypedActor;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.kernel.Bootable;

public class HelloKernel implements Bootable {
  final ActorSystem system = ActorSystem.create("hellokernel");

  public static class HelloActor extends UntypedActor {
    final ActorRef worldActor = getContext().actorOf(
        Props.create(WorldActor.class));

    public void onReceive(Object message) {
      if (message == "start")
        worldActor.tell("Hello", getSelf());
      else if (message instanceof String)
        System.out.println(String.format("Received message '%s'", message));
      else
        unhandled(message);
    }
  }

  public static class WorldActor extends UntypedActor {
    public void onReceive(Object message) {
      if (message instanceof String)
        getSender().tell(((String) message).toUpperCase() + " world!",
            getSelf());
      else
        unhandled(message);
    }
  }

  public void startup() {
    system.actorOf(Props.create(HelloActor.class)).tell("start", null);
  }

  public void shutdown() {
    system.shutdown();
  }
}