public abstract class Actor implements Runnable {

    @Setter @Getter private String actorId;
    private final BlockingQueue<Message> mailbox = new LinkedBlockingQueue<>();
    private volatile boolean active = true; 


    public void send(Message message) {
        mailbox.add(message); 
    }

    public void stop() {
        active = false; 
    }

    @Override
    public void run() {
        
    }

    protected abstract void onReceive(Message message);
}

@AllArgsConstructor
@Getter
@Setter
public class Message {
    private final String content;
    private final String senderId;
}

public class ActorSystem {
    public void startActor(Actor actor) {
        String actorId = "actor-" + idCounter.incrementAndGet(); // Generate a new and unique ID
        actor.setActorId(actorId); // assign the actor it's ID
        actorRegister.put(actorId, actor); // Register and save the actor with it's ID
        executor.submit(actor); // Run the actor in a thread
    }
    public Actor getActorById(String actorId) {
        return actorRegister.get(actorId); //  Find by Id
    }

    public void shutdown() {
        executor.shutdownNow(); // Stop all threads
    }
}

public class App {
  public static void main(String[] args) {
    ActorSystem system = new ActorSystem();
      Actor srijan = new ExampleActor(system);
      Actor ansh = new ExampleActor2(system);

      system.startActor(srijan);
      system.startActor(ansh);
      ansh.send(new Message("Hello ansh", srijan.getActorId()));
      srijan.send(new Message("Hello srijan!", ansh.getActorId()));

      Thread.sleep(1000); // Give time for messages to process

      srijan.stop(); // Stop the actor gracefully
      ansh.stop();
      system.shutdown(); // Stop the actor system
  }
}