javax.management
Class NotificationBroadcasterSupport

java.lang.Object
  |
  +--javax.management.NotificationBroadcasterSupport

All Implemented Interfaces:

NotificationBroadcaster, NotificationEmitter

Direct Known Subclasses:

Monitor, RelationService, Timer

public class NotificationBroadcasterSupport

extends java.lang.Object

implements NotificationEmitter

Provides an implementation of NotificationEmitter interface. This can be used as the super class of an MBean that sends notifications.

It is not specified whether the notification dispatch model is synchronous or asynchronous. That is, when a thread calls sendNotification, the NotificationListener.handleNotification method of each listener may be called within that thread (a synchronous model) or within some other thread (an asynchronous model).

Applications should not depend on notification dispatch being synchronous or being asynchronous. Thus:

• Applications should not assume a synchronous model. When the sendNotification method returns, it is not guaranteed that every listener's handleNotification method has been called. It is not guaranteed either that a listener will see notifications in the same order as they were generated. Listeners that depend on order should use the sequence number of notifications to determine their order (see Notification.getSequenceNumber()).
• Applications should not assume an asynchronous model. If the actions performed by a listener are potentially slow, the listener should arrange for them to be performed in another thread, to avoid holding up other listeners and the caller of sendNotification.

Author:

Young Yang

Constructor Summary

NotificationBroadcasterSupport()

Method Summary

void	addNotificationListener(NotificationListener listener, NotificationFilter filter, java.lang.Object handback) Adds a listener.
MBeanNotificationInfo[]	getNotificationInfo() Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.
protected void	handleNotification(NotificationListener listener, Notification notif, java.lang.Object handback) This method is called by sendNotification for each listener in order to send the notification to that listener.
void	removeNotificationListener(NotificationListener listener) Removes a listener.
void	removeNotificationListener(NotificationListener listener, NotificationFilter filter, java.lang.Object handback) Removes a listener from this MBean.
void	sendNotification(Notification notification) Sends a notification.

Methods inherited from class java.lang.Object

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

Constructor Detail

NotificationBroadcasterSupport

public NotificationBroadcasterSupport()

Method Detail

addNotificationListener

public void addNotificationListener(NotificationListener listener,
                                    NotificationFilter filter,
                                    java.lang.Object handback)

Adds a listener.

Specified by:

addNotificationListener in interface NotificationBroadcaster

Parameters:

listener - The listener to receive notifications.

filter - The filter object. If filter is null, no filtering will be performed before handling notifications.

handback - An opaque object to be sent back to the listener when a notification is emitted. This object cannot be used by the Notification broadcaster object. It should be resent unchanged with the notification to the listener.

Throws:

java.lang.IllegalArgumentException - thrown if the istener is null.

See Also:

removeNotificationListener(javax.management.NotificationListener)

removeNotificationListener

public void removeNotificationListener(NotificationListener listener)
                                throws ListenerNotFoundException

Removes a listener. Note that if the listener has been registered with different handback objects or notification filters, all entries corresponding to the listener will be removed.

Specified by:

removeNotificationListener in interface NotificationBroadcaster

Parameters:

listener - the listener to receive notifications.

Throws:

ListenerNotFoundException

removeNotificationListener

public void removeNotificationListener(NotificationListener listener,
                                       NotificationFilter filter,
                                       java.lang.Object handback)
                                throws ListenerNotFoundException

Description copied from interface: NotificationEmitter

Removes a listener from this MBean. The MBean must have a listener that exactly matches the given listener, filter, and handback parameters. If there is more than one such listener, only one is removed.

The filter and handback parameters may be null if and only if they are null in a listener to be removed.

Specified by:

removeNotificationListener in interface NotificationEmitter

Parameters:

listener - A listener that was previously added to this MBean.

filter - The filter that was specified when the listener was added.

handback - The handback that was specified when the listener was added.

Throws:

ListenerNotFoundException - The listener is not registered with the MBean, or it is not registered with the given filter and handback.

getNotificationInfo

public MBeanNotificationInfo[] getNotificationInfo()

Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.

Specified by:

getNotificationInfo in interface NotificationBroadcaster

sendNotification

public void sendNotification(Notification notification)

Sends a notification. A listener will be removed if an exception appears when calling the listener's handleNotification method.

Parameters:

notification -

handleNotification

protected void handleNotification(NotificationListener listener,
                                  Notification notif,
                                  java.lang.Object handback)

This method is called by sendNotification for each listener in order to send the notification to that listener. It can be overridden in subclasses to change the behaviour of notification delivery, for instance to deliver the notification in a separate thread.

It is not guaranteed that this method is called by the same thread as the one that called sendNotification.

The default implementation of this method is equivalent to

 listener.handleNotification(notif, handback);
 

Parameters:

listener - the listener to which the notification is being delivered.

notif - the notification being delivered to the listener.

handback - the handback object that was supplied when the listener was added.

Since:

JMX 1.2