Akka服务端客户端编写hellword

akka版本：2.3.6.（不同版本由于api不同，实现可能不同）

    <dependency>

        <groupId>com.typesafe.akka</groupId>

        <artifactId>akka-actor_2.11</artifactId>

         <version>2.3.6</version>

    </dependency>

    <dependency>

        <groupId>com.typesafe.akka</groupId>

        <artifactId>akka-remote_2.11</artifactId>

         <version>2.3.6</version>

    </dependency>

    <dependency>

        <groupId>com.typesafe.akka</groupId>

        <artifactId>akka-slf4j_2.11</artifactId>

         <version>2.3.6</version>

    </dependency>

服务端：

package com.akka;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import akka.actor.ActorRef;import akka.actor.ActorSystem;import akka.actor.Props;import akka.actor.UntypedActor;import akka.event.Logging;import akka.event.LoggingAdapter;import com.typesafe.config.Config;import com.typesafe.config.ConfigFactory;public class HelloWorld extends UntypedActor{LoggingAdapter log = Logging.getLogger(getContext().system(), this);public static void main( String[] args ) throws Exception{ActorSystem system = ActorSystem.create("test",createConfig());ActorRef actorRef = system.actorOf(Props.create(HelloWorld.class),"helloWorld");System.out.println(actorRef.path());actorRef.tell("启动", ActorRef.noSender());//System.out.println(system.settings());//actorRef.tell("test1", null);//ActorSelection actorSel = system.actorSelection("akka.tcp://test@127.0.0.1:2552/user/helloWorld");//actorSel.tell("test client", ActorRef.noSender());}    @Override    public void onReceive(Object message) throws Exception {                if (message instanceof String) {log.info("Received String message: {}", message);getSender().tell("Received String message:"+message, getSelf());} else{log.info("Exception String message: {}", message);}    }        public static Config createConfig() {          Map<String, Object> map = new HashMap<String, Object>();  //        map.put("akka.loglevel", "ERROR");  //        map.put("akka.stdout-loglevel", "ERROR");            //开启akka远程调用          map.put("akka.actor.provider", "akka.remote.RemoteActorRefProvider");                    List<String> remoteTransports = new ArrayList<String>();          remoteTransports.add("akka.remote.netty.tcp");          map.put("akka.remote.enabled-transports", remoteTransports);                    map.put("akka.remote.netty.tcp.hostname", "127.0.0.1");          map.put("akka.remote.netty.tcp.port", 2552);                    map.put("akka.remote.netty.tcp.maximum-frame-size", 100 * 1024 * 1024);                    //forkjoinpool默认线程数 max(min(cpu线程数 * parallelism-factor, parallelism-max), 8)          map.put("akka.actor.default-dispatcher.fork-join-executor.parallelism-factor", "50");          map.put("akka.actor.default-dispatcher.fork-join-executor.parallelism-max", "50");                   return ConfigFactory.parseMap(map);      }      }

客户端：

package com.akka;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import akka.actor.ActorRef;import akka.actor.ActorSelection;import akka.actor.ActorSystem;import com.typesafe.config.Config;import com.typesafe.config.ConfigFactory;public class Client {public static void main( String[] args ) throws Exception{ActorSystem system = ActorSystem.create("test",createConfig());ActorSelection actorSel = system.actorSelection("akka.tcp://test@127.0.0.1:2552/user/helloWorld");actorSel.tell("test client 1", ActorRef.noSender());Thread.sleep(2000);actorSel.tell("test client 2", ActorRef.noSender());Thread.sleep(2000);actorSel.tell("test client 3", ActorRef.noSender());Thread.sleep(2000);actorSel.tell("test client 4", ActorRef.noSender());Thread.sleep(2000);actorSel.tell("test client 5", ActorRef.noSender());//system.shutdown();}public static Config createConfig() {      Map<String, Object> map = new HashMap<String, Object>();  //    map.put("akka.loglevel", "ERROR");  //    map.put("akka.stdout-loglevel", "ERROR");      //开启akka远程调用      map.put("akka.actor.provider", "akka.remote.RemoteActorRefProvider");            List<String> remoteTransports = new ArrayList<String>();      remoteTransports.add("akka.remote.netty.tcp");      map.put("akka.remote.enabled-transports", remoteTransports);            map.put("akka.remote.netty.tcp.hostname", "127.0.0.1");      map.put("akka.remote.netty.tcp.port", 2553);            map.put("akka.remote.netty.tcp.maximum-frame-size", 100 * 1024 * 1024);            //forkjoinpool默认线程数 max(min(cpu线程数 * parallelism-factor, parallelism-max), 8)      map.put("akka.actor.default-dispatcher.fork-join-executor.parallelism-factor", "50");      map.put("akka.actor.default-dispatcher.fork-join-executor.parallelism-max", "50");           return ConfigFactory.parseMap(map);  }  }

本来想，在本地起服务，本地调用，但是总是连接不到服务端，无法发送消息。后来找到问题，似乎服务器和客户端都得加配置：

 map.put("akka.actor.provider","akka.remote.RemoteActorRefProvider");  

默认是local。加了这个配置后可以正常通信。而且hostname客户端调用的时候，必须与服务端设置的一样，否则还是连接失败。

2:become/unbecome

用context.become方法可以使用新的消息循环处理替换当前的消息处理器，被替换的消息处理器被压到一个栈结构，支持消息处理器的出栈和入栈。使用unbecome出栈。

替换消息处理后，onreceive逻辑使用become后的消息处理。