Java tutorial
/* * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.management; /** * 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. * <P> * To receive MBeanServerNotifications, you need to register a listener with * the {@link MBeanServerDelegate MBeanServerDelegate} MBean * that represents the MBeanServer. The ObjectName of the MBeanServerDelegate is * {@link MBeanServerDelegate#DELEGATE_NAME}, which is * <CODE>JMImplementation:type=MBeanServerDelegate</CODE>. * * <p>The following code prints a message every time an MBean is registered * or unregistered in the MBean Server {@code mbeanServer}:</p> * * <pre> * 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); * </pre> * * <p id="group"> * An MBean which is not an {@link MBeanServerDelegate} may also emit * MBeanServerNotifications. In particular, there is a convention for * MBeans to emit an MBeanServerNotification for a group of MBeans.</p> * * <p>An MBeanServerNotification emitted to denote the registration or * unregistration of a group of MBeans has the following characteristics: * <ul><li>Its {@linkplain Notification#getType() notification type} is * {@code "JMX.mbean.registered.group"} or * {@code "JMX.mbean.unregistered.group"}, which can also be written {@link * MBeanServerNotification#REGISTRATION_NOTIFICATION}{@code + ".group"} or * {@link * MBeanServerNotification#UNREGISTRATION_NOTIFICATION}{@code + ".group"}. * </li> * <li>Its {@linkplain #getMBeanName() MBean name} is an ObjectName pattern * that selects the set (or a superset) of the MBeans being registered * or unregistered</li> * <li>Its {@linkplain Notification#getUserData() user data} can optionally * be set to an array of ObjectNames containing the names of all MBeans * being registered or unregistered.</li> * </ul> * * <p> * MBeans which emit these group registration/unregistration notifications will * declare them in their {@link MBeanInfo#getNotifications() * MBeanNotificationInfo}. * </p> * * @since 1.5 */ public class MBeanServerNotification extends Notification { /* Serial version */ private static final long serialVersionUID = 2876477500475969677L; /** * Notification type denoting that an MBean has been registered. * Value is "JMX.mbean.registered". */ public static final String REGISTRATION_NOTIFICATION = "JMX.mbean.registered"; /** * Notification type denoting that an MBean has been unregistered. * Value is "JMX.mbean.unregistered". */ public static final String UNREGISTRATION_NOTIFICATION = "JMX.mbean.unregistered"; /** * @serial The object names of the MBeans concerned by this notification */ private final ObjectName objectName; /** * Creates an MBeanServerNotification object specifying object names of * the MBeans that caused the notification and the specified notification * type. * * @param type A string denoting the type of the * notification. Set it to one these values: {@link * #REGISTRATION_NOTIFICATION}, {@link * #UNREGISTRATION_NOTIFICATION}. * @param source The MBeanServerNotification object responsible * for forwarding MBean server notification. * @param sequenceNumber A sequence number that can be used to order * received notifications. * @param objectName The object name of the MBean that caused the * notification. * */ public MBeanServerNotification(String type, Object source, long sequenceNumber, ObjectName objectName) { super(type, source, sequenceNumber); this.objectName = objectName; } /** * Returns the object name of the MBean that caused the notification. * * @return the object name of the MBean that caused the notification. */ public ObjectName getMBeanName() { return objectName; } @Override public String toString() { return super.toString() + "[mbeanName=" + objectName + "]"; } }