scala - 如何在 Akka 远程参与者之间发送消息？

Question

我想建一个非常简单的聊天应用程序，它应该可以在没有使用 Akka 远程角色的中央服务器的情况下工作。

我基本上想用 IP 地址 A 启动应用程序的一个实例。
然后我想用 IP 地址 A 启动应用程序的一个实例，并告诉它远程实例位于 IP 地址 B。

我将如何设置它？ Akka 文档通常只涵盖客户端/服务器用例，甚至基本的东西也让我完全困惑，例如。 G。在哪里使用 Actor.actorOf对比 Actor.register对比 Actor.remote .

我的代码目前看起来像这样:

import collection.mutable.{ArrayBuffer, HashSet}
import akka.actor.Actor

sealed trait Event    
/** Join tells the peer that there is a new peer and 
  * requests a list of known peers and messages. */
case class Join(user: String, ipAddress: String) extends Event
/** Join tells the peer that there is a new peer. */
case class Register(user: String, ipAddress: String) extends Event
case class Leave(user: String, ipAddress: String) extends Event    
case object GetChatLog extends Event
case object GetPeers extends Event
case class ChatLog(log: Seq[Message]) extends Event
case class Peers(peers: Seq[Peer]) extends Event
case class Message(sender: String, time: Long, message: String) extends Event

class ChatPeer(val name: String, ipAddress: String) extends Actor {
  val chat = Actor.remote.actorFor("chat:service", ipAddress, 2552) //This is not what I want...
  val messages = ArrayBuffer[Message]()
  val peers = HashSet[Peer]()

  def join = {
    (chat ? Join(name, ipAddress)).as[(Seq[Peer], Seq[Message])]
  }

  def register = chat ! Register(name, ipAddress)

  def leave = chat ! Leave(name, ipAddress)

  def send(message: String) = {
    val msg = Message(name, System.currentTimeMillis(), message)
    messages += msg
    chat ! msg
  }

  def getMessages = (chat ? GetChatLog).as[ChatLog]
    .getOrElse(throw new Exception("Couldn't get the chat log from ChatServer"))

  def getPeers = (chat ? GetPeers).as[Peers]
    .getOrElse(throw new Exception("Couldn't get the peers from ChatServer"))


  def receive = {
    case msg@Message(from, time, message) =>
      println(msg)
      messages += msg

    case GetChatLog =>
      self reply messages

    case GetPeers =>
      self reply peers

    case Join =>
      peers += Peer(name, ipAddress)
      self reply ((peers, messages))

    case Register(user, ipAddress) =>
      peers += Peer(user, ipAddress)

    case Leave(user, ipAddress) =>
      peers -= Peer(user, ipAddress)

  }
}

case class Peer(name: String, ipAddress: String)

Answer 1

不确定我是否理解您从示例代码中想要的内容。

我认为，如果你想制作一个没有专用服务器的版本，那么基本上两个对等点都必须启动并注册一个远程服务器

remote.start("localhost", somePort).register("chat-main", actorOf[ChatMain])

然后尝试连接到对方的服务器

val otherActor = remote.actorFor("chat-main", otherHost, somePeer)

基本上，您必须同时创建对等服务器和客户端。设置的其余部分是一些协商和聊天逻辑，但从技术上讲，它并不比 Akka 网站上的简单示例复杂多少。