| /* |
| * Copyright (c) 2009, 2010, 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 com.sun.org.glassfish.external.amx; |
| |
| import java.util.Set; |
| import javax.management.MBeanServer; |
| import javax.management.MBeanServerConnection; |
| import javax.management.MBeanServerNotification; |
| import javax.management.Notification; |
| import javax.management.NotificationListener; |
| import javax.management.ObjectName; |
| import java.util.concurrent.CountDownLatch; |
| |
| import static com.sun.org.glassfish.external.amx.AMX.*; |
| |
| /** |
| * Listens for registration of MBeans of various types. |
| * Intended usage is for subsystems to lazy-load only when the Parent |
| * MBean is registered. |
| */ |
| @com.sun.org.glassfish.external.arc.Taxonomy(stability = com.sun.org.glassfish.external.arc.Stability.UNCOMMITTED) |
| public class MBeanListener<T extends MBeanListener.Callback> implements NotificationListener |
| { |
| private static void debug(final Object o) { System.out.println( "" + o ); } |
| |
| /** listen for MBeans in a given domain of a given type[name] |
| OR an ObjectName (below) */ |
| private final String mJMXDomain; |
| private final String mType; |
| private final String mName; |
| |
| /** mType and mName should be null if mObjectName is non-null, and vice versa */ |
| private final ObjectName mObjectName; |
| |
| private final MBeanServerConnection mMBeanServer; |
| |
| private final T mCallback; |
| |
| public String toString() |
| { |
| return "MBeanListener: ObjectName=" + mObjectName + ", type=" + mType + ", name=" + mName; |
| } |
| |
| public String getType() |
| { |
| return mType; |
| } |
| |
| public String getName() |
| { |
| return mName; |
| } |
| |
| public MBeanServerConnection getMBeanServer() |
| { |
| return mMBeanServer; |
| } |
| |
| /** Callback interface. */ |
| public interface Callback |
| { |
| public void mbeanRegistered(final ObjectName objectName, final MBeanListener listener); |
| public void mbeanUnregistered(final ObjectName objectName, final MBeanListener listener); |
| } |
| |
| /** |
| Default callback implementation, can be subclassed if needed |
| Remembers only the last MBean that was seen. |
| */ |
| public static class CallbackImpl implements MBeanListener.Callback |
| { |
| private volatile ObjectName mRegistered = null; |
| private volatile ObjectName mUnregistered = null; |
| private final boolean mStopAtFirst; |
| |
| public CallbackImpl() { |
| this(true); |
| } |
| |
| public CallbackImpl(final boolean stopAtFirst) |
| { |
| mStopAtFirst = stopAtFirst; |
| } |
| |
| public ObjectName getRegistered() { return mRegistered; } |
| public ObjectName getUnregistered() { return mUnregistered; } |
| |
| protected final CountDownLatch mLatch = new CountDownLatch(1); |
| |
| /** Optional: wait for the CountDownLatch to fire |
| If used, the subclass should countDown() the latch when the |
| appropriate event happens |
| */ |
| public void await() |
| { |
| try |
| { |
| mLatch.await(); // wait until BootAMXMBean is ready |
| } |
| catch (InterruptedException e) |
| { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| public void mbeanRegistered(final ObjectName objectName, final MBeanListener listener) |
| { |
| mRegistered = objectName; |
| if ( mStopAtFirst ) |
| { |
| listener.stopListening(); |
| } |
| } |
| public void mbeanUnregistered(final ObjectName objectName, final MBeanListener listener) |
| { |
| mUnregistered = objectName; |
| if ( mStopAtFirst ) |
| { |
| listener.stopListening(); |
| } |
| } |
| } |
| |
| public T getCallback() |
| { |
| return mCallback; |
| } |
| |
| /** |
| * Listener for a specific MBean. |
| * Caller must call {@link #start} to start listening. |
| * @param server |
| * @param objectName |
| * @param callback |
| */ |
| public MBeanListener( |
| final MBeanServerConnection server, |
| final ObjectName objectName, |
| final T callback) |
| { |
| mMBeanServer = server; |
| mObjectName = objectName; |
| mJMXDomain = null; |
| mType = null; |
| mName = null; |
| mCallback = callback; |
| } |
| |
| /** |
| * Listener for all MBeans of specified type, with or without a name. |
| * Caller must call {@link #start} to start listening. |
| * @param server |
| * @param type type of the MBean (as found in the ObjectName) |
| * @param callback |
| */ |
| public MBeanListener( |
| final MBeanServerConnection server, |
| final String domain, |
| final String type, |
| final T callback) |
| { |
| this(server, domain, type, null, callback); |
| } |
| |
| /** |
| * Listener for MBeans of specified type, with specified name (or any name |
| * if null is passed for the name). |
| * Caller must call {@link #start} to start listening. |
| * @param server |
| * @param type type of the MBean (as found in the ObjectName) |
| * @param name name of the MBean, or null if none |
| * @param callback |
| */ |
| public MBeanListener( |
| final MBeanServerConnection server, |
| final String domain, |
| final String type, |
| final String name, |
| final T callback) |
| { |
| mMBeanServer = server; |
| mJMXDomain = domain; |
| mType = type; |
| mName = name; |
| mObjectName = null; |
| mCallback = callback; |
| } |
| |
| |
| private boolean isRegistered( final MBeanServerConnection conn, final ObjectName objectName ) |
| { |
| try |
| { |
| return conn.isRegistered(objectName); |
| } |
| catch (final Exception e) |
| { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| Start listening. If the required MBean(s) are already present, the callback |
| will be synchronously made before returning. It is also possible that the |
| callback could happen twice for the same MBean. |
| */ |
| public void startListening() |
| { |
| // race condition: must listen *before* looking for existing MBeans |
| try |
| { |
| mMBeanServer.addNotificationListener( AMXUtil.getMBeanServerDelegateObjectName(), this, null, this); |
| } |
| catch (final Exception e) |
| { |
| throw new RuntimeException("Can't add NotificationListener", e); |
| } |
| |
| if ( mObjectName != null ) |
| { |
| if ( isRegistered(mMBeanServer, mObjectName) ) |
| { |
| mCallback.mbeanRegistered(mObjectName, this); |
| } |
| } |
| else |
| { |
| // query for AMX MBeans of the requisite type |
| String props = TYPE_KEY + "=" + mType; |
| if (mName != null) |
| { |
| props = props + "," + NAME_KEY + mName; |
| } |
| |
| final ObjectName pattern = AMXUtil.newObjectName(mJMXDomain + ":" +props); |
| try |
| { |
| final Set<ObjectName> matched = mMBeanServer.queryNames(pattern, null); |
| for (final ObjectName objectName : matched) |
| { |
| mCallback.mbeanRegistered(objectName, this); |
| } |
| } |
| catch( final Exception e ) |
| { |
| throw new RuntimeException(e); |
| } |
| } |
| } |
| |
| |
| /** unregister the listener */ |
| public void stopListening() |
| { |
| try |
| { |
| mMBeanServer.removeNotificationListener( AMXUtil.getMBeanServerDelegateObjectName(), this); |
| } |
| catch (final Exception e) |
| { |
| throw new RuntimeException("Can't remove NotificationListener " + this, e); |
| } |
| } |
| |
| public void handleNotification( |
| final Notification notifIn, |
| final Object handback) |
| { |
| if (notifIn instanceof MBeanServerNotification) |
| { |
| final MBeanServerNotification notif = (MBeanServerNotification) notifIn; |
| final ObjectName objectName = notif.getMBeanName(); |
| |
| boolean match = false; |
| if ( mObjectName != null && mObjectName.equals(objectName) ) |
| { |
| match = true; |
| } |
| else if ( objectName.getDomain().equals( mJMXDomain ) ) |
| { |
| if ( mType != null && mType.equals(objectName.getKeyProperty(TYPE_KEY)) ) |
| { |
| final String mbeanName = objectName.getKeyProperty(NAME_KEY); |
| if (mName != null && mName.equals(mbeanName)) |
| { |
| match = true; |
| } |
| } |
| } |
| |
| if ( match ) |
| { |
| final String notifType = notif.getType(); |
| if (MBeanServerNotification.REGISTRATION_NOTIFICATION.equals(notifType)) |
| { |
| mCallback.mbeanRegistered(objectName, this); |
| } |
| else if (MBeanServerNotification.UNREGISTRATION_NOTIFICATION.equals(notifType)) |
| { |
| mCallback.mbeanUnregistered(objectName, this); |
| } |
| } |
| } |
| } |
| |
| } |