/**
   * This method is used to register a listener with the service. The method
   * should: 1. Check to see if there is a list of listener with the listener
   * name, create one if the listener list doesn't exit 2. Add the new listener
   * to the listener list
   * 
   * @param listener
   */
  public void addListener(Listener listener) {
  ...
  }

/**
   * This method is used to broadcast an event. This method should: 1. Check if
   * there is a list of listener that listen to the event name. 2. If there is a
   * list of listener, create the event object with the given name , source and
   * data 3. For each listener in the listener list, invoke the method
   * onEvent(Event)
   * 
   * @param <S> The type of the source that broadcast the event
   * @param <D> The type of the data that the source object is working on
   * @param name The name of the event
   * @param source The source object instance
   * @param data The data object instance
   * @throws Exception 
   */
  public <S, D> void broadcast(String name, S source, D data) throws Exception {
  ...
  }

  /**
   * This method is used when a developer want to implement his own event object
   * and broadcast the event. The method should: 1. Check if there is a list of
   * listener that listen to the event name. 2. If there is a list of the
   * listener, For each listener in the listener list, invoke the method
   * onEvent(Event)
   * 
   * @param <T> The type of the event object, the type of the event object has
   *          to be extended from the Event type
   * @param event The event instance
   * @throws Exception
   */
  public <T extends Event> void broadcast(T event) throws Exception {
  ...
  }

public abstract class Listener<S, D> extends BaseComponentPlugin {

  /**
   * This method should be invoked when an event with the same name is
   * broadcasted
   */
  public abstract void onEvent(Event<S, D> event) throws Exception;

}

public interface ComponentPlugin {
  public String getName();

  public void setName(String name);

  public String getDescription();

  public void setDescription(String description);
}

<?xml version="1.0" encoding="ISO-8859-1"?>
<configuration>
...
	<external-component-plugins>
		<!-- The full qualified name of the ListenerService --> 
		<target-component>org.exoplatform.services.listener.ListenerService</target-component>

		<component-plugin>
			<!-- The name of the listener that is also the name of the target event -->
			<name>${name-of-the-target-event}</name>
			<!-- The name of the method to call on the ListenerService in order to register the Listener -->
			<set-method>addListener</set-method>
			<!-- The full qualified name of the Listener -->
			<type>${the-FQN-of-the-listener}</type>
		</component-plugin>

	</external-component-plugins>

</configuration>

listenerService.broadcast("exo.core.security.ConversationRegistry.register", this, state);

<?xml version="1.0" encoding="ISO-8859-1"?>
<configuration>
...
	<external-component-plugins>
		<!-- The full qualified name of the ListenerService --> 
		<target-component>org.exoplatform.services.listener.ListenerService</target-component>

		<component-plugin>
			<!-- The name of the listener that is also the name of the target event -->
			<name>exo.core.security.ConversationRegistry.register</name>
			<!-- The name of the method to call on the ListenerService in order to register the Listener -->
			<set-method>addListener</set-method>
			<!-- The full qualified name of the Listener -->
			<type>org.exoplatform.forum.service.AuthenticationLoginListener</type>
		</component-plugin>

	</external-component-plugins>

</configuration>
...