一目瞭然，也不用多說了，隨便記錄下

TestEvent

public class TestEvent {
    private final int message;
    public TestEvent(int message) {        
        this.message = message;
        System.out.println("event message:"+message);
    }
    public int getMessage() {
        return message;
    }
}

EventListener

import com.google.common.eventbus.Subscribe;

public class EventListener {
    public int lastMessage = 0;

    @Subscribe
    public void listen(TestEvent event) {
        lastMessage = event.getMessage();
        System.out.println("Message:"+lastMessage);
    }

    public int getLastMessage() {      
        
 
return lastMessage;
    }
}

TestEventBus

import com.google.common.eventbus.EventBus;

public class TestEventBus {

    public static void main(String[] args) throws Exception {

        EventBus eventBus = new EventBus("test");
        EventListener listener = new EventListener();

        eventBus.register(listener);

        eventBus.post(
 
new TestEvent(200));
        eventBus.post(new TestEvent(300));
        eventBus.post(new TestEvent(400));

        System.out.println("LastMessage:"+listener.getLastMessage());
        ;
    }
}

 列印結果

event message:200
Message:200
event message:300
Message:300
event message:400
Message:400
LastMessage:400