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	Description
static final String	REGISTRATION_NOTIFICATION	Notification type denoting that an MBean has been registered.
static final String	UNREGISTRATION_NOTIFICATION	Notification type denoting that an MBean has been unregistered.

Fields declared in class Notification

source

Modifier and Type	Field	Description
protected Object	source	This field hides the EventObject.source field in the parent class to make it non-transient and therefore part of the serialized form.

Constructor Summary

Constructors

Constructor	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

Modifier and Type	Method	Description
ObjectName	getMBeanName()	Returns the object name of the MBean that caused the notification.

Methods declared in class Notification

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

Modifier and Type	Method	Description
String	getMessage()	Get the notification message.
long	getSequenceNumber()	Get the notification sequence number.
long	getTimeStamp()	Get the notification timestamp.
String	getType()	Get the notification type.
Object	getUserData()	Get the user data.
void	setSequenceNumber(long sequenceNumber)	Set the notification sequence number.
void	setSource(Object source)	Sets the source.
void	setTimeStamp(long timeStamp)	Set the notification timestamp.
void	setUserData(Object userData)	Set the user data.
String	toString()	Returns a String representation of this notification.

Methods declared in class EventObject

getSource

Modifier and Type	Method	Description
Object	getSource()	The object on which the Event initially occurred.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Answers a new instance of the same class as the receiver, whose slots have been filled in with the values in the slots of the receiver.
boolean	equals(Object o)	Compares the argument to the receiver, and answers true if they represent the same object using a class specific comparison.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. May cause performance issues, deadlocks and hangs.
final Class<? extends Object>	getClass()	Answers the unique instance of java.lang.Class which represents the class of the receiver.
int	hashCode()	Answers an integer hash code for the receiver.
final void	notify()	Causes one thread which is waiting on the receiver to be made ready to run.
final void	notifyAll()	Causes all threads which are waiting on the receiver to be made ready to run.
final void	wait()	Causes the thread which sent this message to be made not ready to run pending some change in the receiver (as indicated by notify or notifyAll).
final void	wait(long time)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.
final void	wait(long time, int frac)	Causes the thread which sent this message to be made not ready to run either pending some change in the receiver (as indicated by notify or notifyAll) or the expiration of the timeout.

Field Details

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 Details

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 Details

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.