FSM

Question

我有一个有某些背景的演员，即

def step2: Receive = {
  case _ => log error "Unhandled message"
}

def step1: Receive = {
  case _ => log error "Unhandled message"
}

有没有办法知道演员当前处于哪个州（step1，step2）？（我可以在string上存储值，但我想知道是否有更好的方法。）

如果不可能，我想理解为什么因为这个状态应该保留在某个地方。

Answer 1

FSM

您可以使用FSM。 stateName给出了州名。

使用在每个状态中处理的特殊消息对Actor进行Ping操作以发送stateName。

sealed trait ExampleState
case object State1 extends ExampleState
case object State2 extends ExampleState
case object C extends ExampleState

import akka.actor.{Actor, FSM}
import akka.event.EventHandler
import akka.util.duration._

case object Move

class ABC extends Actor with FSM[ExampleState, Unit] {

  import FSM._

  startWith(State1, Unit)

  when(State1) {
    case Ev(Move) =>
      EventHandler.info(this, "Go to B and move on after 5 seconds")
      goto(state2) forMax (5 seconds)
  }

  when(State2) {
    case Ev(StateTimeout) =>
      EventHandler.info(this, "Moving to C")
      goto(C)
  }

  when(C) {
    case Ev(Move) =>
      EventHandler.info(this, "Stopping")
      stop
  }

  initialize // this checks validity of the initial state and sets up timeout if needed
}

Hacky Solution

Akka Actor不存储有关PartialFunction的任何特定信息。所以我认为没有一个akka lib功能可以随时使用。

在actor中有state，然后在Actor尝试成为某个东西时更新状态。

class FooBar extends Actor with ActorLogging {

  var state: Option[String] = Some("receive")

  override def receive: Receive = {
    case _ => context become state1()
  }

  def state1: () => Receive = {
    () => {

      state = Some("state1")

      {
        case _ => log error "ignore"
      }
    }
  }


  def state2: () => Receive = {
    () => {

      state = Some("state2")

      {
        case _ => log error "ignore"
      }
    }
  }


}

有没有办法知道Akka演员的背景？

1 个答案:

FSM

Hacky Solution