Akka Java API - 如何扩展AbstractActor并使用Timers和Stash函数

Question

基本上我想要一个使用Timers和Stash功能的Actor。

在Scala，我们可以做以下 - extends AbstractActor with Timer with Stash

在Java中，我发现了两个类 - AbstractActorWithTimers和AbstractActorWithStash。

不幸的是，我无法扩展Java中的两个类。

任何推荐的方式在Java中这样做？

Answer 1

即使我遇到了同样的问题。我想创建一个状态机，我需要stash和timer。

所以在这种情况下，我有两种选择： -

• 使用AbstractFSMWithStash： - 我这样做 - 不喜欢，因为我不确定它是否是我的解决方案中的scalabel
• 使用Typed Actors，你可以实际组成定时器和藏匿，请参考下面的代码与测试用例： -

  import akka.actor.testkit.typed.javadsl.TestKitJunitResource;
  import akka.actor.typed.ActorRef;
  import akka.actor.typed.Behavior;
  import akka.actor.typed.javadsl.Behaviors;
  import akka.actor.typed.javadsl.StashBuffer;
  import akka.actor.typed.javadsl.TimerScheduler;
  import org.junit.ClassRule;
  import org.junit.Test;
  import org.scalatest.junit.JUnitSuite;
  
  import java.time.Duration;
  
  public class CountingActor extends JUnitSuite {
  
    public static final class DeviceMessage implements Msg{
      private int id;
  
      public DeviceMessage(int id) {
        this.id = id;
      }
  
      public int getId() {
        return id;
      }
    }
  
    interface Msg{}
    private static final class TimeOut implements Msg{}
  
  
    private static final Object TIMER_KEY = new Object();
  
    private static final StashBuffer<Msg> buffer = StashBuffer.create(10000);
  
    public static Behavior<Msg> behavior(Duration after) {
      return Behaviors.withTimers(timers -> active(timers, after));
    }
  
  
    private static Behavior<Msg> idle(TimerScheduler<Msg> timers,
        Duration after) {
      return Behaviors.receive(Msg.class)
        .onMessage(DeviceMessage.class, (ctx, msg) -> {
            System.out.println("in idle state got message:"+msg.getId());
            buffer.stash(msg);
          return Behaviors.same();
        })
        .onMessage(TimeOut.class,(ctx,msg)->{
            System.out.println("in idle state got TimeOut");
            timers.cancel(TIMER_KEY);
            return buffer.unstashAll(ctx,active(timers,after));
        })
        .build();
    }
  
    private static Behavior<Msg> active(TimerScheduler<Msg> timers,
       Duration after) {
      return Behaviors.receive(Msg.class)
        .onMessage(DeviceMessage.class, (ctx, msg) -> {
            System.out.println("got message:"+msg.getId());
            timers.startSingleTimer(TIMER_KEY, new TimeOut(), after);
            System.out.println(" going to idle state " );
            return idle(timers,after);
        })
  
        .build();
      }
  
      @ClassRule
      public static final TestKitJunitResource testKit = new TestKitJunitResource();
  
      @Test
      public void stashingExample() throws Exception {
          ActorRef<Msg> ref= testKit.spawn(CountingActor.behavior(Duration.ofSeconds(2)));
  
          for(int i=0;;i++){
              ref.tell(new DeviceMessage(i));
          }
  
  
     }
  
  }