public class MBeanServerNotification extends Notification
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:
"JMX.mbean.registered.group"
or "JMX.mbean.unregistered.group"
, which can also be written REGISTRATION_NOTIFICATION
+ ".group"
or UNREGISTRATION_NOTIFICATION
+ ".group"
. MBeans which emit these group registration/unregistration notifications will declare them in their MBeanNotificationInfo
.
public static final String REGISTRATION_NOTIFICATION
Notification type denoting that an MBean has been registered. Value is "JMX.mbean.registered".
public static final String UNREGISTRATION_NOTIFICATION
Notification type denoting that an MBean has been unregistered. Value is "JMX.mbean.unregistered".
public MBeanServerNotification(String type, Object source, long sequenceNumber, ObjectName objectName)
Creates an MBeanServerNotification object specifying object names of the MBeans that caused the notification and the specified notification type.
type
- A string denoting the type of the notification. Set it to one these values: REGISTRATION_NOTIFICATION
, UNREGISTRATION_NOTIFICATION
.source
- The MBeanServerNotification object responsible for forwarding MBean server notification.sequenceNumber
- A sequence number that can be used to order received notifications.objectName
- The object name of the MBean that caused the notification.public ObjectName getMBeanName()
Returns the object name of the MBean that caused the notification.
public String toString()
Description copied from class: Notification
Returns a String representation of this notification.
toString
in class Notification
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