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遵循文档示例(2.1.4)后,我在加载微内核的actor处理消息时遇到了问题,其中可引导扩展类定义如下:

class HelloKernel extends Bootable {
  val system = ActorSystem("hellokernel")
  def startup = {
    system.actorOf(Props[HelloActor]) ! Start  
  }
  def shutdown = {
    system.shutdown()
  }
}

如果创建了一个虚拟(即未在代码中的其他任何地方使用)实例,如下所示,则消息将按预期进行处理。

class HelloKernel extends Bootable {
  val system = ActorSystem("hellokernel")

  val dummyActor = system.actorOf(Props[HelloActor])

  def startup = {
    system.actorOf(Props[HelloActor]) ! Start  
  }
  def shutdown = {
    system.shutdown()
  }
}

是否确实存在虚拟实例化,或者通过这样做,我是否会造成一些副作用,从而导致消息被处理?

根据 Thomas Letschert 在Akka 2.1 最小远程参与者示例中给出的代码,我将服务器端变成了微内核托管的参与者。

import akka.actor.Actor
import akka.actor.ActorLogging
import akka.actor.ActorSystem
import akka.actor.Props
import akka.kernel.Bootable


class Joe extends Actor {
  def receive = {
    case msg: String => println("joe received " + msg + " from " + sender)
    case _ => println("Received unknown msg ")
  }
}

class GreetServerKernel extends Bootable {
  val system = ActorSystem("GreetingSystem")
  val joe = system.actorOf(Props[Joe], name = "joe")
  println(joe.path)
  joe ! "local msg!"
  println("Server ready")

  def startup = {
  }

  def shutdown = {
    println("PrimeWorker: Shutting Down")
    system.shutdown
  }

}

在这种情况下,当删除消息时不处理的虚拟实例化是

  val joe = system.actorOf(Props[Joe], name = "joe")

调用者代码是

import akka.actor._
import akka.actor.ActorDSL._

object GreetSender extends App {
  implicit val system = ActorSystem("GreetingSystem")
  val joe = system.actorFor("akka://GreetingSystem@127.0.0.1:2554/user/joe")

  println(joe.path)

  val a = actor(new Act {
    whenStarting { joe ! "Hello Joe from remote" }
  })

  joe ! "Hello"

  println("Client has sent Hello to joe")
}
4

1 回答 1

1

如果您发布的代码确实准确,那么只需将实例的joe实例移入startup操作而不是可启动类的构造函数中:

def startup = {
  system.actorOf(Props[Joe], name = "joe")
}

joe在有人可以通过名称查找它并向其发送消息之前,需要启动与名称相关联的演员。这与在可引导类的构造函数中启动它基本上是一样的,但我相信约定要求在startup函数中进行所有参与者实例化,而不是可引导类主体(因此构造函数)

于 2013-05-20T16:48:37.347 回答