org.bushe.swing.event.annotation
Annotation Type EventSubscriber

@Retention(value=RUNTIME)
@Target(value=METHOD)
public @interface EventSubscriber

An Annotation for subscribing to EventService Events.

This annotation simplifies much of the repetitive boilerplate used for subscribing to EventService Events.

Instead of this:

 public class MyAppController implements EventSubscriber {
   public MyAppController {
      EventBus.subscribe(AppClosingEvent.class, this);
   }
   public void onEvent(EventServiceEvent event) {
      AppClosingEvent appClosingEvent = (AppClosingEvent)event;
      //do something
   }
 }
 

You can do this:

 public class MyAppController {  //no interface necessary
   public MyAppController {
       AnnotationProcessor.process(this);//if not using AOP
   }
   @EventSubscriber
   public void onAppClosingEvent(AppClosingEvent appClosingEvent) {//Use your own method name with typesafety
      //do something
   }
 }
 

That's pretty good, but when the controller does more, annotations are even nicer.

 public class MyAppController implements EventSubscriber {
   public MyAppController {
      EventBus.subscribe(AppStartingEvent.class, this);
      EventBus.subscribe(AppClosingEvent.class, this);
   }
   public void onEvent(EventServiceEvent event) {
      //wicked bad pattern, but we have to this
      //...or create multiple subscriber classes and hold instances of them fields, which is even more verbose...
      if (event instanceof AppStartingEvent) {
         onAppStartingEvent((AppStartingEvent)event);
      } else (event instanceof AppClosingEvent) {
         onAppStartingEvent((AppClosingEvent)event);
      }

   }

   public void onAppStartingEvent(AppStartingEvent appStartingEvent) {
      //do something
   }

   public void onAppClosingEvent(AppClosingEvent appClosingEvent) {
      //do something
   }
 }
 

You can do this:

 public class MyAppController {
   public MyAppController {
       AnnotationProcessor.process(this);//this line can be avoided with a compile-time tool or an Aspect
   }
   @EventSubscriber(eventClass=AppStartingEvent.class)
   public void onAppStartingEvent(AppStartingEvent appStartingEvent) {
      //do something
   }
   @EventSubscriber(eventClass=AppAppClosingEvent.class)
   public void onAppClosingEvent(AppClosingEvent appClosingEvent) {
      //do something
   }
 }
 

Brief, clear, and easy.

Optional Element Summary

java.lang.Class<? extends EventService>	autoCreateEventServiceClass Whether or not to autocreate the event service if it doesn't exist on subscription, default is true.
java.lang.Class	eventClass The class to subscribe to, if not specified, a subscription is created for the type of the method parameter.
java.lang.String	eventServiceName The event service to subscribe to, default to the EventServiceLocator.SERVICE_NAME_EVENT_BUS.
boolean	exact Whether or not to subscribe to the exact class or a class hierarchy, defaults to class hierarchy (false).
int	priority Determines the order in which this subscriber is called, default is FIFO.
ReferenceStrength	referenceStrength Whether to subscribe weakly or strongly.

eventClass

public abstract java.lang.Class eventClass

The class to subscribe to, if not specified, a subscription is created for the type of the method parameter.

Default:

org.bushe.swing.event.annotation.UseTheClassOfTheAnnotatedMethodsParameter.class

priority

public abstract int priority

Determines the order in which this subscriber is called, default is FIFO.

Default:

0

exact

public abstract boolean exact

Whether or not to subscribe to the exact class or a class hierarchy, defaults to class hierarchy (false).

Default:

false

referenceStrength

public abstract ReferenceStrength referenceStrength

Whether to subscribe weakly or strongly.

Default:

org.bushe.swing.event.annotation.ReferenceStrength.WEAK

eventServiceName

public abstract java.lang.String eventServiceName

The event service to subscribe to, default to the EventServiceLocator.SERVICE_NAME_EVENT_BUS.

Default:

"EventBus"

autoCreateEventServiceClass

public abstract java.lang.Class<? extends EventService> autoCreateEventServiceClass

Whether or not to autocreate the event service if it doesn't exist on subscription, default is true. If the service needs to be created, it must have a default constructor.

Default:

org.bushe.swing.event.ThreadSafeEventService.class