Question

我在Java中使用Akka类型的actor。我有一个BatchManager是控制器的接口，一个JobManager创建一些工作者并执行一个工作。 JobManager看起来像

interface JobManager {
    public Future<String> execute();
    public Future<AwaitableBatchStatusResponse> awaitCompletion();
    public Future<BatchStatusResponse> getStatus();
    public Future<String> reloadFailures();
    public void jobComplete(JobMessage message);
}

其中Future为scala.concurrent.Future。实现类会覆盖所有这些方法，特别是

class JobManagerImpl implements JobManager {
    public JobManagerImpl() { 
        System.out.println("JobManagerImpl constructor start");
        // do some stuff
        System.out.println("JobMangerImpl constructor end");
    }

    @Override
    public Future<String> execute() {
        System.out.println("start execute on jobmanager");
        // do some stuff
        System.out.println("end execute in jobmanager");
        return Futures.successful("blah");
    }
}

JobManager正在构建成功（只要我在构造函数的末尾打印出“JobMangerImpl构造函数结束”）。但是，BatchManager然后在新execute上调用JobManager，并且我被告知该消息将出现死信（以及线程标题中的错误 - 堆栈跟踪在下面）。我在JobManagerImpl＃execute中的printlns没有运行。

Enqueue job: d90c4d58-3142-48cd-8f3e-96e75d4ca7d1
Execute job: d90c4d58-3142-48cd-8f3e-96e75d4ca7d1
start create job manager in poll
JobManagerImpl constructor start : d90c4d58-3142-48cd-8f3e-96e75d4ca7d1
JobMangerImpl constructor end
end create jobManager in poll
begin execute in batchmanager
end execute in batchmanager
JobManagerImpl constructor start : d90c4d58-3142-48cd-8f3e-96e75d4ca7d1
JobMangerImpl constructor end
[INFO] [07/15/2015 15:36:07.088] [PerformanceAsync-akka.actor.default-dispatcher-10] [akka://PerformanceAsync/deadLetters] Message [java.lang.String] from Actor[akka://PerformanceAsync/user/StandardJobManager#1902186473] to Actor[akka://PerformanceAsync/deadLetters] was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[ERROR] [07/15/2015 15:36:07.089] [PerformanceAsync-akka.actor.default-dispatcher-8] [akka://PerformanceAsync/user/StandardJobManager/StandardJobManager:d90c4d58-3142-48cd-8f3e-96e75d4ca7d1:JobManager] Class akka.actor.TypedActor$MethodCall can not access a member of class com.async.JobManager with modifiers "public abstract"
java.lang.IllegalAccessException: Class akka.actor.TypedActor$MethodCall can not access a member of class com.async.JobManager with modifiers "public abstract"
    at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:101)
    at java.lang.reflect.AccessibleObject.slowCheckMemberAccess(AccessibleObject.java:295)
    at java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:287)
    at java.lang.reflect.Method.invoke(Method.java:476)
    at akka.actor.TypedActor$MethodCall.apply(TypedActor.scala:145)
    at akka.actor.TypedActor$TypedActor$$anonfun$receive$1$$anonfun$applyOrElse$2.apply(TypedActor.scala:311)
    at akka.actor.TypedActor$TypedActor.withContext(TypedActor.scala:299)
    at akka.actor.TypedActor$TypedActor$$anonfun$receive$1.applyOrElse(TypedActor.scala:306)
    at akka.actor.Actor$class.aroundReceive(Actor.scala:465)
    at akka.actor.TypedActor$TypedActor.aroundReceive(TypedActor.scala:246)
    at akka.actor.ActorCell.receiveMessage(ActorCell.scala:516)
    at akka.actor.ActorCell.invoke(ActorCell.scala:487)
    at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:238)
    at akka.dispatch.Mailbox.run(Mailbox.scala:220)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

我很难过 - 我用公共方法覆盖了所有JobManager方法，为什么Akka不能接触到它们？

Answer 1

看来问题是我在JobManagerImpl的静态内部类中创建了BatchManagerImpl - 这个内部类在TypedActor.get(TypedActor.context())没有＆＃39的奇怪处境中; t抛出一个在TypedActor上下文之外使用的异常，但是以这种方式实例化的任何东西都在内部被破坏。

Answer 2

我猜，TypedActor方法调用使用的是类JobManager而不是JobManagerImpl。

虽然你/ Akka已经实例化了JobManagerImpl，因为我们可以看到构造函数SOP，但是Akka试图通过反射来调用方法，但它使用类JobManager.class代替JobManagerImpl.class。 JobManager.class作为一个接口，将其所有方法都作为 “公共抽象” 方法，这些方法可以在异常堆栈跟踪中看到。

我不确定你是否有任何地方传递Class<?>个物品。请查看。

类akka.actor.TypedActor $ MethodCall无法使用修饰符“public abstract”访问类JobManager的成员

2 个答案: