如果 Future 调用失败，则让 actor 失败

Question

我将在未来的通话中执行某些操作。我将在成功完成时将结果返回给发送者，或者如果未来的调用失败，则让参与者失败。这将由实现具有监督策略的 RoundRobinPool 的父级处理。

这里是代码sn-p。

private def getData(sender: ActorRef): Unit = {

    dao.getData().mapTo[List[Data]].map(result => sender ! result)
      .onFailure {
        case e: NullPointerExcetpion => {
          println("+++++++ Throwing exception")
      // throwning the exception from here doesn't cause the supervisor to restart this actor
          throw t
        }
      }

      // throwing the exception from here makes the supervisor strategy to take action
      throw new NullPointerExcetpion

  }

如果future返回异常，我们如何让actor失败？

干杯，

乌萨夫

Answer 1

问题在于onFailure 回调是从任意线程抛出的，而不是actor 正在运行的线程。您可以做的是将结果传递给自己，然后抛出：

case class MyFailure(e: Throwable)

def receive: {
  case MyFailure(e) => throw e
}

private def getData(sender: ActorRef): Unit = {
  dao
   .getData()
   .mapTo[List[Data]]
   .recover {
     case e => MyFailure(e)
   }
   .pipeTo(self)
}

或者正如@jrudolph 建议的那样：

def receive: {
  case Status.Failure(e) => throw e
}

private def getData(sender: ActorRef): Unit = {
  dao
   .getData()
   .mapTo[List[Data]]
   .pipeTo(self)
}