Question

Java 8（好吧，Groovy）在这里使用Akka com.typesafe.akka:akka-actor_2.11:2.5.4。我试图创建一个创建/拥有/管理另一个角色（AppMaster）的角色（StateChecker）并计划发送此StateChecker一条CheckState消息每4秒钟一次：

class CheckState {}

class StateChecker extends AbstractActor {
  // For this question, it really doesn't matter what this actor does
}

class AppMaster extends AbstractActor {
    ActorRef stateChecker

    @Override
    Receive createReceive() {
      receiveBuilder()
            .match(Init, { message ->
              stateChecker = context.actorOf(Props.create(StateChecker, "yes", 20), "state-checker")

              FiniteDuration startDur = Duration.Zero()

              FiniteDuration freqDur = Duration.create(4000, TimeUnit.MILLISECONDS)
              CheckState checkState = new CheckState()
              ExecutionContextExecutor executor = context.system().dispatcher()

              context.system().scheduler().schedule(startDur, freqDur, stateChecker, checkState,
                executor)
            })
        .build()
    }
}

当我运行时，我得到以下异常：

groovy.lang.MissingMethodException: No signature of method: akka.actor.LightArrayRevolverScheduler.schedule() is applicable for argument types: (scala.concurrent.duration.FiniteDuration, scala.concurrent.duration.FiniteDuration, akka.actor.LocalActorRef, com.me.myapp.messages.CheckState, akka.dispatch.Dispatcher) values: [0 days, 4000 milliseconds, Actor[akka://myapp/user/myapp-master/o1-keeper#-1837899613], ...]
Possible solutions: schedule(scala.concurrent.duration.FiniteDuration, scala.concurrent.duration.FiniteDuration, java.lang.Runnable, scala.concurrent.ExecutionContext), schedule(scala.concurrent.duration.FiniteDuration, scala.concurrent.duration.FiniteDuration, scala.Function0, scala.concurrent.ExecutionContext), schedule(scala.concurrent.duration.FiniteDuration, scala.concurrent.duration.FiniteDuration, akka.actor.ActorRef, java.lang.Object, scala.concurrent.ExecutionContext, akka.actor.ActorRef)
    at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapter.java:58)
    at org.codehaus.groovy.runtime.callsite.PojoMetaClassSite.call(PojoMetaClassSite.java:49)

我在日志语句中添加了，并且在调度期间抛出了异常：

context.system().scheduler().schedule(startDur, freqDur, stateChecker, checkState,
  executor)

知道我需要做些什么才能解决这个问题？由于这是我在Akka的Java API中遇到的问题，我做需要通过Java API获得答案。

Answer 1

问题是您传递给#include <stdio.h> int main() { const int i=1; int a[i]; printf("Hello World"); return 0; }方法的参数不匹配该方法的重载版本。您可以在JavaDoc中看到schedule()的重载版本的签名。

您尝试使用的版本是以下method：

schedule()

您错过了最后一个参数，即Cancellable schedule(scala.concurrent.duration.FiniteDuration initialDelay, scala.concurrent.duration.FiniteDuration interval, ActorRef receiver, java.lang.Object message, scala.concurrent.ExecutionContext executor, ActorRef sender)被指定为已安排消息的发件人。如果ActorRef并不关心向谁发送StateChecker消息，那么最简单的解决方法是将CheckState作为最后一个参数传递：

null

Java Akka Scheduling API抛出MissingMethodException

1 个答案: