Java 应用程序事件 : Difference between @EventListener annotation and ApplicationListener interface

Question

我正在使用 Java ApplicationEvents 来发布然后订阅监听事件。 @EventListener 注解和 ApplicationListener 接口(interface)有什么区别。有什么区别或相同的功能吗？

资源:https://reflectoring.io/spring-boot-application-events-explained/

方法一:

@Component
class UserRemovedListener {

  @EventListener(condition = "#event.name eq 'reflectoring'")
  void handleConditionalListener(UserRemovedEvent event) {
    // handle UserRemovedEvent
  }
}

方法2:

@Component
class UserCreatedListener implements ApplicationListener<UserCreatedEvent> {

  @Override
  public void onApplicationEvent(UserCreatedEvent event) {
    // handle UserCreatedEvent
  }
}

Answer 1

根据文档，它们几乎相同

There are two ways to define a listener. We can either use the @EventListener annotation or implement the ApplicationListener interface. In either case, the listener class has to be managed by Spring.Blockquote

但是如果你使用@EvenListener，它会自动注册ApplicationListener。整个报价是:

Starting with Spring 4.1 it’s now possible to simply annotate a method of a managed bean with @EventListener to automatically register an ApplicationListener matching the signature of the method

在官方网站中，文档还解释说注释使其更易于使用并且更短。链接应该是:https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/context/event/EventListener.html

https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/context/ApplicationListener.html

希望这有帮助。