Represents a notification emitted by the MBean Server through the MBeanServerDelegate MBean. The MBean Server emits the following types of notifications: MBean registration, MBean unregistration.
To receive MBeanServerNotifications, you need to register a listener with the MBeanServerDelegate
MBean that represents the MBeanServer. The ObjectName of the MBeanServerDelegate is MBeanServerDelegate.DELEGATE_NAME
, which is JMImplementation:type=MBeanServerDelegate
.
The following code prints a message every time an MBean is registered or unregistered in the MBean Server mbeanServer
:
private static final NotificationListener printListener = new NotificationListener() {
public void handleNotification(Notification n, Object handback) {
if (!(n instanceof MBeanServerNotification)) {
System.out.println("Ignored notification of class " + n.getClass().getName());
return;
}
MBeanServerNotification mbsn = (MBeanServerNotification) n;
String what;
if (n.getType().equals(MBeanServerNotification.REGISTRATION_NOTIFICATION))
what = "MBean registered";
else if (n.getType().equals(MBeanServerNotification.UNREGISTRATION_NOTIFICATION))
what = "MBean unregistered";
else
what = "Unknown type " + n.getType();
System.out.println("Received MBean Server notification: " + what + ": " +
mbsn.getMBeanName());
}
};
...
mbeanServer.addNotificationListener(
MBeanServerDelegate.DELEGATE_NAME, printListener, null, null);
An MBean which is not an MBeanServerDelegate
may also emit MBeanServerNotifications. In particular, there is a convention for MBeans to emit an MBeanServerNotification for a group of MBeans.
An MBeanServerNotification emitted to denote the registration or unregistration of a group of MBeans has the following characteristics:
- Its notification type is
"JMX.mbean.registered.group"
or "JMX.mbean.unregistered.group"
, which can also be written REGISTRATION_NOTIFICATION
+ ".group"
or UNREGISTRATION_NOTIFICATION
+ ".group"
.
- Its MBean name is an ObjectName pattern that selects the set (or a superset) of the MBeans being registered or unregistered
- Its user data can optionally be set to an array of ObjectNames containing the names of all MBeans being registered or unregistered.
MBeans which emit these group registration/unregistration notifications will declare them in their MBeanNotificationInfo
.