Class MBeanServerNotification

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.

Fields

REGISTRATION_NOTIFICATION

public static final String REGISTRATION_NOTIFICATION

Notification type denoting that an MBean has been registered. Value is "JMX.mbean.registered".

See Also:

Constant Field Values

UNREGISTRATION_NOTIFICATION

public static final String UNREGISTRATION_NOTIFICATION

Notification type denoting that an MBean has been unregistered. Value is "JMX.mbean.unregistered".

See Also:

Constant Field Values

Constructors

MBeanServerNotification

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.

Parameters:

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.

Methods

getMBeanName

public ObjectName getMBeanName()

Returns the object name of the MBean that caused the notification.

Returns:

the object name of the MBean that caused the notification.

toString

public String toString()

Description copied from class: Notification

Returns a String representation of this notification.

Overrides:

toString in class Notification

Returns:

A String representation of this notification.