Akka简单例子

简介：

        今天打算写一个关于Redis压测的小程序，想来反正也是花时间写，不如顺便研究一下Akka这个比较火的开源库。

        代码是scala写得，建议大家尝试新技术！

hello word 小例子：

pom.xml 

<dependency>
	<groupId>com.typesafe.akka</groupId>
	<artifactId>akka-actor_2.11</artifactId>
	<version>2.3.9</version>
</dependency>

 HelloActor.scala

/**
  * Created by zz on 2016/9/27.
  */
import akka.actor.Actor
import akka.actor.ActorSystem
import akka.actor.Props

case object Person extends Per{
  val name:String="job"
  val age:Int=18
}

class RunRedisActor extends Actor {
  def receive = {
    case "hello" => {println("hello word")}
    case Person => println("ren")
    case _       => println("您是?")
  }
}

object Main extends App {
  val system = ActorSystem("TestRedisSystem")
  // 缺省的Actor构造函数
  val runRedisActor = system.actorOf(Props[RunRedisActor], name = "helloactor")
  runRedisActor ! "hello"
  runRedisActor ! Person
  runRedisActor ! "喂"
}

运行结果：

hello word
ren
您是?

Process finished with exit code -1

 注意：akka2.4.X 版本会以后错误，原因是jdk1.7及以下版本不兼容。

报错信息 写道

Exception in thread "main" java.lang.UnsupportedClassVersionError: JVMCFRE003 主要版本错误；类=akka/actor/ActorSystem$，偏移量=6
at java.lang.ClassLoader.defineClassImpl(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:295)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:154)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:711)
at java.net.URLClassLoader.access$400(URLClassLoader.java:92)
at java.net.URLClassLoader$ClassFinder.run(URLClassLoader.java:1159)
at java.security.AccessController.doPrivileged(AccessController.java:314)
at java.net.URLClassLoader.findClass(URLClassLoader.java:594)
at java.lang.ClassLoader.loadClassHelper(ClassLoader.java:743)
at java.lang.ClassLoader.loadClass(ClassLoader.java:711)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:325)
at java.lang.ClassLoader.loadClass(ClassLoader.java:690)
at com.test.lus.akka.Main$.delayedEndpoint$com$test$lus$akka$Main$1(HelloActor.scala:25)
at com.test.lus.akka.Main$delayedInit$body.apply(HelloActor.scala:24)
at scala.Function0$class.apply$mcV$sp(Function0.scala:34)
at scala.runtime.AbstractFunction0.apply$mcV$sp(AbstractFunction0.scala:12)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.App$$anonfun$main$1.apply(App.scala:76)
at scala.collection.immutable.List.foreach(List.scala:381)
at scala.collection.generic.TraversableForwarder$class.foreach(TraversableForwarder.scala:35)
at scala.App$class.main(App.scala:76)
at com.test.lus.akka.Main$.main(HelloActor.scala:24)
at com.test.lus.akka.Main.main(HelloActor.scala)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:88)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:55)
at java.lang.reflect.Method.invoke(Method.java:613)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:144)

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进阶：我们实现简单分布式，远程调用actor

pom.xml 中添加远程依赖：

<dependency>
	<groupId>com.typesafe.akka</groupId>
	<artifactId>akka-remote_2.11</artifactId>
	<version>2.3.9</version>
</dependency>

 application.conf akka默认使用com.typesafe读取配置文件

MyRemoteServerSideActor {
  akka {
    actor {
      provider = "akka.remote.RemoteActorRefProvider"
    }
    remote {
      enabled-transports = ["akka.remote.netty.tcp"]
      netty.tcp {
        hostname = "127.0.0.1"
        port = 2552
      }
    }
  }
}

MyRemoteClientSideActor {
  akka {
    actor {
      provider = "akka.remote.RemoteActorRefProvider"
    }
  }
}

 RemoteActor

import akka.actor.{Actor}

/**
  * Created by zz on 2016/9/27.
  */
class RemoteActor extends Actor{

  def receive = {
    case "remote" => println("remote")
      sender() ! "ok"
  }
}

 AkkaServerApplication

import akka.actor.{ActorSystem, Props}
import com.typesafe.config.ConfigFactory

/**
  * Created by zz on 2016/9/27.
  */
object  AkkaServerApplication extends App {
  val system = ActorSystem("remote-system", ConfigFactory.load().getConfig("MyRemoteServerSideActor")) // 创建名称为remote-system的ActorSystem：从配置文件application.conf中获取该Actor的配置内容
  val log = system.log
  log.info("Remote server actor started: " + system)

  system.actorOf(Props[RemoteActor], "remoteActor") // 创建一个名称为remoteActor的Actor，返回一个ActorRef，这里我们不需要使用这个返回值
}

 ClientActor

import akka.actor.{Actor, ActorLogging}

/**
  * Created by zz on 2016/9/27.
  */
class ClientActor extends Actor with ActorLogging {

  // akka.<protocol>://<actor system>@<hostname>:<port>/<actor path>
  val path = "akka.tcp://[email protected]:2552/user/remoteActor" // 远程Actor的路径，通过该路径能够获取到远程Actor的一个引用
  val remoteServerRef = context.actorSelection(path) // 获取到远程Actor的一个引用，通过该引用可以向远程Actor发送消息

  def receive = {
    case "remote" => remoteServerRef ! "remote"
      println("please go to request client ....")
    case "ok" =>println("server is ok")
  }

}

 AkkaClientApplication

import akka.actor.{ActorSystem, Props}
import com.typesafe.config.ConfigFactory

/**
  * Created byzz on 2016/9/27.
  */
object AkkaClientApplication extends App {

  val system = ActorSystem("client-system", ConfigFactory.load().getConfig("MyRemoteClientSideActor")) // 通过配置文件application.conf配置创建ActorSystem系统
  val clientActor = system.actorOf(Props[ClientActor], "clientActor") // 获取到ClientActor的一个引用

  clientActor ! "remote"

}

AkkaServerApplication输出 写道

[INFO] [09/27/2016 17:01:52.580] [main] [Remoting] Starting remoting
[INFO] [09/27/2016 17:01:52.917] [main] [Remoting] Remoting started; listening on addresses :[akka.tcp://[email protected]:2552]
[INFO] [09/27/2016 17:01:52.919] [main] [Remoting] Remoting now listens on addresses: [akka.tcp://[email protected]:2552]
[INFO] [09/27/2016 17:01:52.931] [main] [ActorSystem(remote-system)] Remote server actor started: akka://remote-system
remote

AkkaClientApplication输出 写道

[INFO] [09/27/2016 17:02:00.080] [main] [Remoting] Starting remoting
[INFO] [09/27/2016 17:02:00.511] [main] [Remoting] Remoting started; listening on addresses :[akka.tcp://[email protected]:2552]
[INFO] [09/27/2016 17:02:00.513] [main] [Remoting] Remoting now listens on addresses: [akka.tcp://[email protected]:2552]
please go to request client ....
server is ok

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再进阶：ping pong demo

PingPong.scala

import akka.actor.{Actor, ActorRef}

/**
  * Created by zz on 2016/9/27.
  */
  case object PingMessage
  case object PongMessage
  case object StartMessage
  case object StopMessage

  class Ping(pong: ActorRef) extends Actor
  {
    var count = 0
    def incrementAndPrint { count += 1; println("ping") }
    def receive = {
      case StartMessage =>
        incrementAndPrint
        pong ! PingMessage
      case PongMessage =>
        if (count > 9) {
          sender ! StopMessage
          println("ping stopped")
          context.stop(self)
        } else {
          incrementAndPrint
          sender ! PingMessage
        }
    }
  }

  class Pong extends Actor {
    def receive = {
      case PingMessage =>
        println("  pong")
        sender ! PongMessage
      case StopMessage =>
        println("pong stopped")
        context.stop(self)
        context.system.shutdown()
    }
}

PingPongApp

import akka.actor.{ActorSystem, Props}


/**
  * Created by zz on 2016/9/27.
  */


object PingPongApp extends App {
  val system = ActorSystem("PingPongSystem")

  val pong = system.actorOf(Props[Pong], name = "pong")
  val ping = system.actorOf(Props(new Ping(pong)), name = "ping")
  // start them going
  ping ! StartMessage
}

输出 写道

ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping
pong
ping stopped
pong stopped

 后记：例子比较简单，但是骨架基本如此，后续再做完善。。。