Module it.rebirthproject.ufoeb

Package it.rebirthproject.ufoeb.eventannotation

Annotation Interface Listen

@Documented
@Retention(RUNTIME)
@Target(METHOD)
public @interface Listen

This annotation must be applied to methods of registered listeners to EventBus. Those methods will be used by the bus system as callbacks to notify listeners about new events of the requested type. Method annotated with Listen must be public, return nothing (void), and have exactly one parameter (the event).

Example:

 Class MagazineReader wants to receive MagazineNews events, so this could be a stub of the class:

 public class MagazineReader {
      @Listen
      public void listenOnMagazineNews(MagazineNewsEvent event) {
          System.out.println("A news arrived: " + event.getNews());
      }
 }

 Class MagazineNewsEvent can be a simple POJO used to carry event's metadata, like this one:

 public class MagazineNewsEvent {

      private final String newsMessage;

      public MagazineNewsEvent(String newsMessage) {
          this.newsMessage = newsMessage;
      }

      public String getNews() {
          return newsMessage;
      }
 }

 The MagazineReader instance must be registered to EventBus to receive news in his listenOnMagazineNews method.

 public static void main(String ... args) {
     MagazineReader magazineReader = new MagazineReader();
     eventBus.register(magazineReader);
     ...
     eventBus.post(new MagazineNewsEvent("Hello Readers!!! Something new just happened..."));
     ...
 }
 

See Also:

• EventBus

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element	Description
int	priority	Listener priority to influence the order of event delivery.

Element Details

priority

int priority

Listener priority to influence the order of event delivery. Higher priority listeners will receive events before others with a lower priority. The default priority is 0 (lowest priority).

Returns:

the listener priority.

Default:

0