public class NotificationBroadcasterSupport extends Object implements NotificationEmitter
Provides an implementation of NotificationEmitter
interface. This can be used as the super class of an MBean that
sends notifications.
By default, the notification dispatch model is synchronous.
That is, when a thread calls sendNotification, the
NotificationListener.handleNotification
method of each listener
is called within that thread. You can override this default
by overriding handleNotification
in a subclass, or by passing an
Executor to the constructor.
If the method call of a filter or listener throws an Exception
,
then that exception does not prevent other listeners from being invoked. However,
if the method call of a filter or of Executor.execute
or of
handleNotification
(when no Excecutor
is specified) throws an
Error
, then that Error
is propagated to the caller of
sendNotification
.
Remote listeners added using the JMX Remote API (see JMXConnector) are not usually called synchronously. That is, when sendNotification returns, it is not guaranteed that any remote listeners have yet received the notification.
Constructor and Description |
---|
NotificationBroadcasterSupport()
Constructs a NotificationBroadcasterSupport where each listener is invoked by the
thread sending the notification.
|
NotificationBroadcasterSupport(Executor executor)
Constructs a NotificationBroadcasterSupport where each listener is invoked using
the given
Executor . |
NotificationBroadcasterSupport(Executor executor,
MBeanNotificationInfo... info)
Constructs a NotificationBroadcasterSupport with information about the notifications that may be sent,
and where each listener is invoked using the given
Executor . |
NotificationBroadcasterSupport(MBeanNotificationInfo... info)
Constructs a NotificationBroadcasterSupport with information
about the notifications that may be sent.
|
Modifier and Type | Method and Description |
---|---|
void |
addNotificationListener(NotificationListener listener,
NotificationFilter filter,
Object handback)
Adds a listener.
|
MBeanNotificationInfo[] |
getNotificationInfo()
Returns an array indicating, for each notification this
MBean may send, the name of the Java class of the notification
and the notification type.
|
protected void |
handleNotification(NotificationListener listener,
Notification notif,
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 from this MBean.
|
void |
removeNotificationListener(NotificationListener listener,
NotificationFilter filter,
Object handback)
Removes a listener from this MBean.
|
void |
sendNotification(Notification notification)
Sends a notification.
|
public NotificationBroadcasterSupport()
NotificationBroadcasterSupport(null, null)
.public NotificationBroadcasterSupport(Executor executor)
Executor
. When sendNotification
is called, a listener is selected if it was added with a null
NotificationFilter
, or if isNotificationEnabled
returns true for the notification being sent. The call to
NotificationFilter.isNotificationEnabled
takes place in the thread
that called sendNotification
. Then, for each selected listener,
executor.execute
is called with a command
that calls the handleNotification
method.
This constructor is equivalent to
NotificationBroadcasterSupport(executor, null)
.executor
- an executor used by the method sendNotification
to
send each notification. If it is null, the thread calling sendNotification
will invoke the handleNotification
method itself.public NotificationBroadcasterSupport(MBeanNotificationInfo... info)
Constructs a NotificationBroadcasterSupport with information
about the notifications that may be sent. Each listener is
invoked by the thread sending the notification. This
constructor is equivalent to NotificationBroadcasterSupport(null, info)
.
If the info
array is not empty, then it is
cloned by the constructor as if by info.clone()
, and
each call to getNotificationInfo()
returns a new
clone.
info
- an array indicating, for each notification this
MBean may send, the name of the Java class of the notification
and the notification type. Can be null, which is equivalent to
an empty array.public NotificationBroadcasterSupport(Executor executor, MBeanNotificationInfo... info)
Constructs a NotificationBroadcasterSupport with information about the notifications that may be sent,
and where each listener is invoked using the given Executor
.
When sendNotification
is called, a
listener is selected if it was added with a null NotificationFilter
, or if isNotificationEnabled
returns true for the notification being sent. The call to
NotificationFilter.isNotificationEnabled
takes
place in the thread that called
sendNotification
. Then, for each selected
listener, executor.execute
is called
with a command that calls the handleNotification
method.
If the info
array is not empty, then it is
cloned by the constructor as if by info.clone()
, and
each call to getNotificationInfo()
returns a new
clone.
executor
- an executor used by the method
sendNotification
to send each notification. If it
is null, the thread calling sendNotification
will
invoke the handleNotification
method itself.info
- an array indicating, for each notification this
MBean may send, the name of the Java class of the notification
and the notification type. Can be null, which is equivalent to
an empty array.public void addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback)
addNotificationListener
in interface NotificationBroadcaster
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.IllegalArgumentException
- thrown if the listener is null.removeNotificationListener(javax.management.NotificationListener)
public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException
NotificationBroadcaster
removeNotificationListener
in interface NotificationBroadcaster
listener
- A listener that was previously added to this
MBean.ListenerNotFoundException
- The listener is not
registered with the MBean.NotificationBroadcaster.addNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)
,
NotificationEmitter.removeNotificationListener(javax.management.NotificationListener, javax.management.NotificationFilter, java.lang.Object)
public void removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws ListenerNotFoundException
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.
removeNotificationListener
in interface NotificationEmitter
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.ListenerNotFoundException
- The listener is not
registered with the MBean, or it is not registered with the
given filter and handback.public MBeanNotificationInfo[] getNotificationInfo()
NotificationBroadcaster
Returns an array indicating, for each notification this MBean may send, the name of the Java class of the notification and the notification type.
It is not illegal for the MBean to send notifications not described in this array. However, some clients of the MBean server may depend on the array being complete for their correct functioning.
getNotificationInfo
in interface NotificationBroadcaster
public void sendNotification(Notification notification)
Executor
was specified in the constructor, it will be given one
task per selected listener to deliver the notification to that listener.notification
- The notification to send.protected void handleNotification(NotificationListener listener, Notification notif, 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 behavior of notification delivery,
for instance to deliver the notification in a separate
thread.
The default implementation of this method is equivalent to
listener.handleNotification(notif, handback);
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. Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
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