javax.management

## Class MBeanServerNotification

- java.lang.Object
- - java.util.EventObject
  - - javax.management.Notification
    - - javax.management.MBeanServerNotification

- All Implemented Interfaces:
    Serializable

      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:

  - 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`.

  Since:
    1.5
  See Also:
    Serialized Form

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static String` | `REGISTRATION_NOTIFICATION` Notification type denoting that an MBean has been registered.
    `static String` | `UNREGISTRATION_NOTIFICATION` Notification type denoting that an MBean has been unregistered.

    - ### Fields inherited from class javax.management.Notification

      `source`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `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.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `ObjectName` | `getMBeanName()` Returns the object name of the MBean that caused the notification.
    `String` | `toString()` Returns a String representation of this notification.

    - ### Methods inherited from class javax.management.Notification

      `getMessage, getSequenceNumber, getTimeStamp, getType, getUserData, setSequenceNumber, setSource, setTimeStamp, setUserData`

    - ### Methods inherited from class java.util.EventObject

      `getSource`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### 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

  - ### Constructor Detail

    - #### 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.

  - ### Method Detail

    - #### 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.

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