Akka 实践之(三) 远程部署

Akka 可以支持客户端和服务端远程部署，这点对与高并发分布式调用非常有利。 在上篇的代码基础上，新增2个类，LookupActor和LookupApplication.java

1、首先看一下类图

2、 源码

在本例中，将远程创建CalculatorActor 对象，然后通过指定path的方式创建这个对象的远程Actor（其实我认为是这个对象的代理）

    final String path = "akka.tcp://[email protected]:8552/user/calculator";
    final ActorRef actor = system.actorOf( Props.create(LookupActor.class, path), "lookupActor");

LookupActor和 LookupApplication的源码如下，重点关注是如何创建远程对象，以及如何获取对远程对象的使用。

package com.cwqsolo.study.akka.demo;

import static java.util.concurrent.TimeUnit.SECONDS;
import scala.concurrent.duration.Duration;
import akka.actor.ActorRef;
import akka.actor.ActorIdentity;
import akka.actor.Identify;
import akka.actor.Terminated;
import akka.actor.UntypedActor;
import akka.actor.ReceiveTimeout;
import akka.japi.Procedure;

public class LookupActor extends UntypedActor {

  private final String path;
  private ActorRef calculator = null;

  public LookupActor(String path) {
    this.path = path;
    sendIdentifyRequest();
  }

  private void sendIdentifyRequest() {
    getContext().actorSelection(path).tell(new Identify(path), getSelf());
    getContext()
        .system()
        .scheduler()
        .scheduleOnce(Duration.create(3, SECONDS), getSelf(),
            ReceiveTimeout.getInstance(), getContext().dispatcher(), getSelf());
  }

  @Override
  public void onReceive(Object message) throws Exception {
    if (message instanceof ActorIdentity) {
      calculator = ((ActorIdentity) message).getRef();
      if (calculator == null) {
        System.out.println("Remote actor not available: " + path);
      } else {
        getContext().watch(calculator);
        getContext().become(active, true);
      }

    } else if (message instanceof ReceiveTimeout) {
      sendIdentifyRequest();

    } else {
      System.out.println("Not ready yet");

    }
  }

  Procedure