akka并发编程练习

用Scala的akka同时向多个节点发送信息（广播）

思路：每个客户端向服务端发送登陆信息后，服务端记录发送者，存入列表中，客户端向服务端发送的其他信息向所有已登录的客户端发送

这个程序实现了消息的简单广播

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首先实现服务端

package com.bit.room

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

import scala.collection.mutable

class TalkServer extends Actor { //伴生类

  val talkerSet = new mutable.HashSet[ActorRef]()

  override def receive: Receive = {
    case "launch" => println("Server on") //接受launch 打印启动

    case "exit" => {  //接受到exit，将发送者从聊天室Set移除
      talkerSet.remove(sender())
      if (talkerSet.nonEmpty) {
        println(sender().toString() + "off")
        talkerSet.foreach(Refs => Refs ! ServerMessage(sender().toString() + "off"))
      }
    }

    case "join" => {
      talkerSet.add(sender()) //接受到join，将发送者加入聊天室
      println(sender().toString() + "on")
      talkerSet.foreach(Refs => Refs ! ServerMessage(sender().toString() + "on"))
    }

    case ClientMessage(msg) => { //接受到其他信息，将其转发给聊天室的其他人
      println(msg)
      talkerSet.foreach(Refs => Refs ! ServerMessage(msg))
    }
  }
}

object TalkServer { //伴生对象
  def main(args: Array[String]): Unit = {
    val host = "127.0.0.1" //ip
    val port = 9000 //端口
    val config = ConfigFactory.parseString( //配置项
      s"""
         |akka.actor.provider="akka.remote.RemoteActorRefProvider"
         |akka.remote.netty.tcp.hostname = $host
         |akka.remote.netty.tcp.port=$port
         """.stripMargin)
    val actorSystem = ActorSystem("Server", config)
    val serverActorRef = actorSystem.actorOf(Props[TalkServer], "talk_server")
    serverActorRef ! "launch"
  }
}

---

实现客户端

package com.bit.room

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

import scala.io.StdIn

class TalkClient(host: String, port: Int) extends Actor {
  var serverActorRef: ActorSelection = _ //服务器代理对象

  override def preStart(): Unit = { //客户端启动，获取服务的的信息
    serverActorRef = context.actorSelection(s"akka.tcp://Server@${host}:${port}/user/talk_server")
  }


  override def receive: Receive = {
    case "start" => println("client on") //启动
    case "join" => serverActorRef ! "join"
    case "exit" => serverActorRef ! "exit"
    case msg: String => { //向服务端发信息
      serverActorRef ! ClientMessage(msg)
    }
    case ServerMessage(msg) => println(msg) //接收到服务端点的信息，打印

  }
}

object TalkClient {
  def main(args: Array[String]): Unit = {
    val host = "127.0.0.1"
    val port = 9001

    val serverHost = "127.0.0.1"
    val serverPort = 9000

    val config = ConfigFactory.parseString(
      s"""
         |akka.actor.provider="akka.remote.RemoteActorRefProvider"
         |akka.remote.netty.tcp.hostname=$host
         |akka.remote.netty.tcp.port=$port
         """.stripMargin)

    val clientSystem = ActorSystem("Client", config)

    val clientActorRef = clientSystem.actorOf(Props(new TalkClient(serverHost, serverPort.toInt)), "talk_client")
    clientActorRef ! "start"

    var flag = true
    while (true) {
      val question = StdIn.readLine()
      if (question.equals("exit")) { //输入exit后，就打印到控制台
        clientActorRef ! question
        flag = false
      }
      if (question.equals("join")) { //输入join后，就发给服务端
        flag = true
      }
      if (flag) {
        clientActorRef ! question
      } else {
        println(question)
      }

    }

  }
}

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由于是在一台机器上进行的实验，启动多个客户端时需要更改端口号