title: Akka simple cluster example
body: <p>I am new to Akka. I am trying the first cluster example in Akka Java Doc. The codes are as follows:</p>
  
  <pre><code>import akka.actor.ActorRef;
  import akka.actor.ActorSystem;
  import akka.actor.Props;
  import akka.actor.UntypedActor;
  import akka.cluster.Cluster;
  import akka.cluster.ClusterEvent.ClusterDomainEvent;
  
  public class SimpleClusterApp {
      public static void main(String[] args) {
      // Override the configuration of the port
      // when specified as program argument
      if (args.length &gt; 0)
          System.setProperty("akka.remote.netty.tcp.port", args[0]);
  
      // Create an Akka system
      ActorSystem system = ActorSystem.create("ClusterSystem");
  
      // Create an actor that handles cluster domain events
      ActorRef clusterListener = system.actorOf(Props.create(SimpleClusterListener.class), "clusterListener");
  
      // Add subscription of cluster events
      Cluster.get(system).subscribe(clusterListener, ClusterDomainEvent.class);
  }
  }
  </code></pre>
  
  <p>But it cannot work. Eclipse complains that the SimpleClusterListener.class cannot be resolved. Could anyone tell me how can I find this class?
  Thank you very much</p>