Package org.exoplatform.services.listener

Class ListenerService

java.lang.Object

org.exoplatform.services.listener.ListenerService

All Implemented Interfaces:

org.picocontainer.Startable

public class ListenerService
extends Object
implements org.picocontainer.Startable

Created by The eXo Platform SAS
Listener Service is reponsible for notifying the Listener when a given event is broadcasted.

Author:

: Nhu Dinh Thuan.

eXo level API

Platform

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected class	ListenerService.AsynchronousListener<S,D>	This AsynchronousListener is a wrapper for original listener, that executes wrapped listeners onEvent() in separate thread.
protected class	ListenerService.RunListener<S,D>	This thread executes listener.onEvent(event) method.

Constructor Summary

Constructors

Constructor	Description
ListenerService(org.exoplatform.container.ExoContainerContext ctx)	Construct a listener service.
ListenerService(org.exoplatform.container.ExoContainerContext ctx, org.exoplatform.container.xml.InitParams params)	Construct a listener service.
ListenerService(org.exoplatform.container.ExoContainerContext ctx, InitialContextInitializer initializer)	Construct a listener service.
ListenerService(org.exoplatform.container.ExoContainerContext ctx, InitialContextInitializer initializer, org.exoplatform.container.xml.InitParams params)	Construct a listener service.

Method Summary

Modifier and Type	Method	Description
void	addListener(String eventName, Listener listener)	This method is used to register a new Listener.
void	addListener(Listener listener)	This method is used to register a Listener to the events of the same name.
<S,D> void	broadcast(String name, S source, D data)	This method is used to broadcast an event.
<T extends Event> void	broadcast(T event)	This method is used when a developer want to implement his own event object and broadcast the event.
void	start()
void	stop()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ListenerService

public ListenerService(org.exoplatform.container.ExoContainerContext ctx)

Construct a listener service.

ListenerService

public ListenerService(org.exoplatform.container.ExoContainerContext ctx,
                       InitialContextInitializer initializer)

Construct a listener service.

ListenerService

public ListenerService(org.exoplatform.container.ExoContainerContext ctx,
                       org.exoplatform.container.xml.InitParams params)

Construct a listener service.

ListenerService

public ListenerService(org.exoplatform.container.ExoContainerContext ctx,
                       InitialContextInitializer initializer,
                       org.exoplatform.container.xml.InitParams params)

Construct a listener service.

Method Detail

addListener

public void addListener(Listener listener)

This method is used to register a Listener to the events of the same name. It is similar to addListener(listener.getName(), listener)

Parameters:

listener - the listener to notify any time an even of the same name is triggered

addListener

public void addListener(String eventName,
                        Listener listener)

This method is used to register a new Listener. Any time an event of the given event name has been triggered, the Listener will be notified. This method will:

1. Check if it exists a list of listeners that have been registered for the given event name, create a new list if no list exists
2. Add the listener to the list

Parameters:

eventName - The name of the event to listen to

listener - The Listener to notify any time the event with the given name is triggered

broadcast

public final <S,D> void broadcast(String name,
                                        S source,
                                        D data)
                                 throws Exception

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)

Type Parameters:

S - The type of the source that broacast the event

D - The type of the data that the source object is working on

Parameters:

name - The name of the event

source - The source object instance

data - The data object instance

Throws:

Exception - if an exception occurs

broadcast

public final <T extends Event> void broadcast(T event)
                                       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, ror each listener in the listener list, invoke the method onEvent(Event)

Type Parameters:

T - The type of the event object, the type of the event object has to be extended from the Event type

Parameters:

event - The event instance

Throws:

Exception

start

public void start()

Specified by:

start in interface org.picocontainer.Startable

stop

public void stop()

Specified by:

stop in interface org.picocontainer.Startable