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")
}