Scala服务器需要管理很多客户端

Question

我们需要用Scala RemotActors创建一个可以处理多个客户端的服务器。例如聊天服务器，它将每个收到的消息回复给所有连接的客户端。我们目前的尝试是为每个客户端创建一个可以收听并回复所有收到的消息的actor。但是演员的动态注册不起作用。

import actors.{Actor, OutputChannel} 
import actors.remote.{RemoteActor, Node, FreshNameCreator} 

object Server extends Actor{ 

    class ConnectedClient(id:Symbol,out:OutputChannel[Any]) extends Actor{ 
     start 

     def act { 
      loop { 
       react { 
        case m:ServerMessage => 
         out ! m 
        case m:ClientMessage => 
         Server ! m 
       } 
      } 
     } 
    } 

    RemoteActor.alive(9999) 
    RemoteActor.register('server, this) //' 
    println("Server started.") 

    var clients = new collection.mutable.HashSet[ConnectedClient] 

    def act { 
     loop { 
      react { 
       case 'connect => //' 
        println("Server: New Client") 
        val id = FreshNameCreator.newName 
        val client = new ConnectedClient(id,sender) 
        clients += client 
        RemoteActor.register(id, client) // This seems not to work 
        reply(id) 
       case ClientMessage(m) => 
        println("Server: received: " + m) 
        for(client <- clients) 
         client ! ServerMessage(m) 
       case m => 
        println("Server: Unknown Message: " + m) 
      } 
     } 
    } 
} 

case class ServerMessage(m:String) 
case class ClientMessage(m:String) 

class Client(serverNode:Node) extends Actor{ 

    println("Client: connecting...") 
    val server = RemoteActor.select(serverNode, 'server) //' 

    start 

    def act{ 

     //we want the symbol that is intended to identify our personal Actor at the Server 
     val id = (server !? 'connect).asInstanceOf[Symbol] //' 
     val personalServer = RemoteActor.select(serverNode, id) 

     println("Client["+id+"]: connected") 

     loop{ 
      react{ 
       case ServerMessage(m) => 
        println("Client["+id+"]: " + m) 
       case m:String => 
        personalServer ! ClientMessage(m) 
       case m => 
        println("Server: Unknown Message: " + m) 
      } 
     } 
    } 
} 

object Main{ 
    def main(args:Array[String]){ 

     Server.start 

     val serverNode = Node("localhost",9999) 
     val clientA = new Client(serverNode) 
     val clientB = new Client(serverNode) 
     val clientC = new Client(serverNode) 

     clientA ! "Hello. I am A." 
     clientB ! "Hello. I am B." 
     clientC ! "Hello. I am C." 
    } 
} 

Answer 1

你必须调用alive和register的act方法内。