jdk/src/share/classes/javax/management/event/EventSubscriber.java
changeset 4159 9e3aae7675f1
parent 4158 0b4d21bc8b5c
parent 4156 acaa49a2768a
child 4160 bda0a85afcb7
--- a/jdk/src/share/classes/javax/management/event/EventSubscriber.java	Wed Oct 21 15:47:09 2009 +0100
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,376 +0,0 @@
-/*
- * Copyright 2008 Sun Microsystems, Inc.  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.  Sun designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
- */
-
-package javax.management.event;
-
-import com.sun.jmx.remote.util.ClassLogger;
-import java.io.IOException;
-import java.lang.ref.WeakReference;
-import java.lang.reflect.Method;
-import java.security.AccessController;
-import java.security.PrivilegedActionException;
-import java.security.PrivilegedExceptionAction;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.WeakHashMap;
-import javax.management.InstanceNotFoundException;
-import javax.management.ListenerNotFoundException;
-import javax.management.MBeanServer;
-import javax.management.MBeanServerConnection;
-import javax.management.MBeanServerDelegate;
-import javax.management.MBeanServerNotification;
-import javax.management.Notification;
-import javax.management.NotificationBroadcaster;
-import javax.management.NotificationFilter;
-import javax.management.NotificationListener;
-import javax.management.ObjectName;
-import javax.management.Query;
-import javax.management.QueryEval;
-import javax.management.QueryExp;
-
-/**
- * <p>An object that can be used to subscribe for notifications from all MBeans
- * in an MBeanServer that match a pattern.  For example, to listen for
- * notifications from all MBeans in the MBeanServer {@code mbs} that match
- * {@code com.example:type=Controller,name=*} you could write:</p>
- *
- * <pre>
- * EventSubscriber subscriber = EventSubscriber.getEventSubscriber(mbs);
- * ObjectName pattern = new ObjectName("com.example:type=Controller,name=*");
- * NotificationListener myListener = ...;
- * NotificationFilter myFilter = null;  // or whatever
- * Object handback = null;              // or whatever
- * subscriber.subscribe(pattern, myListener, myFilter, myHandback);
- * </pre>
- */
-public class EventSubscriber implements EventConsumer {
-    /**
-     * Returns an {@code EventSubscriber} object to subscribe for notifications
-     * from the given {@code MBeanServer}.  Calling this method more
-     * than once with the same parameter may or may not return the same object.
-     *
-     * @param mbs the {@code MBeanServer} containing MBeans to be subscribed to.
-     * @return An {@code EventSubscriber} object.
-     *
-     * @throws NullPointerException if mbs is null.
-     */
-    public static EventSubscriber getEventSubscriber(MBeanServer mbs) {
-        if (mbs == null)
-            throw new NullPointerException("Null MBeanServer");
-
-        EventSubscriber eventSubscriber = null;
-        synchronized (subscriberMap) {
-            final WeakReference<EventSubscriber> wrf = subscriberMap.get(mbs);
-            eventSubscriber = (wrf == null) ? null : wrf.get();
-
-            if (eventSubscriber == null) {
-                eventSubscriber = new EventSubscriber(mbs);
-
-                subscriberMap.put(mbs,
-                        new WeakReference<EventSubscriber>(eventSubscriber));
-            }
-        }
-
-        return eventSubscriber;
-    }
-
-    private EventSubscriber(final MBeanServer mbs) {
-        logger.trace("EventSubscriber", "create a new one");
-        this.mbeanServer = mbs;
-
-        Exception x = null;
-        try {
-            AccessController.doPrivileged(
-                    new PrivilegedExceptionAction<Void>() {
-                public Void run() throws Exception {
-                    mbs.addNotificationListener(
-                            MBeanServerDelegate.DELEGATE_NAME,
-                            myMBeanServerListener, null, null);
-                    return null;
-                }
-            });
-        } catch (PrivilegedActionException ex) {
-            x = ex.getException();
-        }
-
-        // handle possible exceptions.
-        //
-        // Fail unless x is null or x is instance of InstanceNotFoundException
-        // The logic here is that if the MBeanServerDelegate is not present,
-        // we will assume that the connection will not emit any
-        // MBeanServerNotifications.
-        //
-        if (x != null && !(x instanceof InstanceNotFoundException)) {
-            if (x instanceof RuntimeException)
-                throw (RuntimeException) x;
-            throw new RuntimeException(
-                    "Can't add listener to MBean server delegate: " + x, x);
-        }
-    }
-
-    public void subscribe(ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback)
-            throws IOException {
-
-        if (logger.traceOn())
-            logger.trace("subscribe", "" + name);
-
-        if (name == null)
-            throw new IllegalArgumentException("Null MBean name");
-
-        if (listener == null)
-            throw new IllegalArgumentException("Null listener");
-
-        final MyListenerInfo li = new MyListenerInfo(listener, filter, handback);
-        List<MyListenerInfo> list;
-
-        Map<ObjectName, List<MyListenerInfo>> map;
-        Set<ObjectName> names;
-        if (name.isPattern()) {
-            map = patternSubscriptionMap;
-            names = mbeanServer.queryNames(name, notificationBroadcasterExp);
-        } else {
-            map = exactSubscriptionMap;
-            names = Collections.singleton(name);
-        }
-
-        synchronized (map) {
-            list = map.get(name);
-            if (list == null) {
-                list = new ArrayList<MyListenerInfo>();
-                map.put(name, list);
-            }
-            list.add(li);
-        }
-
-        for (ObjectName mbeanName : names) {
-            try {
-                mbeanServer.addNotificationListener(mbeanName,
-                                                    listener,
-                                                    filter,
-                                                    handback);
-            } catch (Exception e) {
-                logger.fine("subscribe", "addNotificationListener", e);
-            }
-        }
-    }
-
-    public void unsubscribe(ObjectName name,
-            NotificationListener listener)
-            throws ListenerNotFoundException, IOException {
-        if (logger.traceOn())
-            logger.trace("unsubscribe", "" + name);
-
-        if (name == null)
-            throw new IllegalArgumentException("Null MBean name");
-
-        if (listener == null)
-            throw new ListenerNotFoundException();
-
-        Map<ObjectName, List<MyListenerInfo>> map;
-        Set<ObjectName> names;
-
-        if (name.isPattern()) {
-            map = patternSubscriptionMap;
-            names = mbeanServer.queryNames(name, notificationBroadcasterExp);
-        } else {
-            map = exactSubscriptionMap;
-            names = Collections.singleton(name);
-        }
-
-        List<MyListenerInfo> toRemove = new ArrayList<MyListenerInfo>();
-        synchronized (map) {
-            List<MyListenerInfo> list = map.get(name);
-            if (list == null) {
-                throw new ListenerNotFoundException();
-            }
-
-            for (MyListenerInfo info : list) {
-                if (info.listener == listener) {
-                    toRemove.add(info);
-                }
-            }
-
-            if (toRemove.isEmpty()) {
-                throw new ListenerNotFoundException();
-            }
-
-            for (MyListenerInfo info : toRemove) {
-                list.remove(info);
-            }
-
-            if (list.isEmpty())
-                map.remove(name);
-        }
-
-        for (ObjectName mbeanName : names) {
-            for (MyListenerInfo i : toRemove) {
-                try {
-                    mbeanServer.removeNotificationListener(mbeanName,
-                        i.listener, i.filter, i.handback);
-                } catch (Exception e) {
-                    logger.fine("unsubscribe", "removeNotificationListener", e);
-                }
-            }
-        }
-    }
-
-    // ---------------------------------
-    // private stuff
-    // ---------------------------------
-    // used to receive MBeanServerNotification
-    private NotificationListener myMBeanServerListener =
-            new NotificationListener() {
-        public void handleNotification(Notification n, Object hb) {
-            if (!(n instanceof MBeanServerNotification) ||
-                    !MBeanServerNotification.
-                    REGISTRATION_NOTIFICATION.equals(n.getType())) {
-                return;
-            }
-
-            final ObjectName name =
-                    ((MBeanServerNotification)n).getMBeanName();
-            try {
-                if (!mbeanServer.isInstanceOf(name,
-                        NotificationBroadcaster.class.getName())) {
-                    return;
-                }
-            } catch (Exception e) {
-                // The only documented exception is InstanceNotFoundException,
-                // which could conceivably happen if the MBean is unregistered
-                // immediately after being registered.
-                logger.fine("myMBeanServerListener.handleNotification",
-                        "isInstanceOf", e);
-                return;
-            }
-
-            final List<MyListenerInfo> listeners = new ArrayList<MyListenerInfo>();
-
-            // If there are subscribers for the exact name that has just arrived
-            // then add their listeners to the list.
-            synchronized (exactSubscriptionMap) {
-                List<MyListenerInfo> exactListeners = exactSubscriptionMap.get(name);
-                if (exactListeners != null)
-                    listeners.addAll(exactListeners);
-            }
-
-            // For every subscription pattern that matches the new name,
-            // add all the listeners for that pattern to "listeners".
-            synchronized (patternSubscriptionMap) {
-                for (ObjectName on : patternSubscriptionMap.keySet()) {
-                    if (on.apply(name)) {
-                        listeners.addAll(patternSubscriptionMap.get(on));
-                    }
-                }
-            }
-
-            // Add all the listeners just found to the new MBean.
-            for (MyListenerInfo li : listeners) {
-                try {
-                    mbeanServer.addNotificationListener(
-                            name,
-                            li.listener,
-                            li.filter,
-                            li.handback);
-                } catch (Exception e) {
-                    logger.fine("myMBeanServerListener.handleNotification",
-                            "addNotificationListener", e);
-                }
-            }
-        }
-    };
-
-    private static class MyListenerInfo {
-        public final NotificationListener listener;
-        public final NotificationFilter filter;
-        public final Object handback;
-
-        public MyListenerInfo(NotificationListener listener,
-                NotificationFilter filter,
-                Object handback) {
-
-            if (listener == null)
-                throw new IllegalArgumentException("Null listener");
-
-            this.listener = listener;
-            this.filter = filter;
-            this.handback = handback;
-        }
-    }
-
-    // ---------------------------------
-    // private methods
-    // ---------------------------------
-    // ---------------------------------
-    // private variables
-    // ---------------------------------
-    private final MBeanServer mbeanServer;
-
-    private final Map<ObjectName, List<MyListenerInfo>> exactSubscriptionMap =
-            new HashMap<ObjectName, List<MyListenerInfo>>();
-    private final Map<ObjectName, List<MyListenerInfo>> patternSubscriptionMap =
-            new HashMap<ObjectName, List<MyListenerInfo>>();
-
-
-
-    // trace issues
-    private static final ClassLogger logger =
-            new ClassLogger("javax.management.event", "EventSubscriber");
-
-    // Compatibility code, so we can run on Tiger:
-    private static final QueryExp notificationBroadcasterExp;
-    static {
-        QueryExp broadcasterExp;
-        try {
-            final Method m = Query.class.getMethod("isInstanceOf", String.class);
-            broadcasterExp = (QueryExp)m.invoke(Query.class,
-                    new Object[] {NotificationBroadcaster.class.getName()});
-        } catch (Exception e) {
-            broadcasterExp = new BroadcasterQueryExp();
-        }
-        notificationBroadcasterExp = broadcasterExp;
-    }
-    private static class BroadcasterQueryExp extends QueryEval implements QueryExp {
-        private static final long serialVersionUID = 1234L;
-        public boolean apply(ObjectName name) {
-            try {
-                return getMBeanServer().isInstanceOf(
-                        name, NotificationBroadcaster.class.getName());
-            } catch (Exception e) {
-                return false;
-            }
-        }
-    }
-
-    private static final
-            Map<MBeanServerConnection, WeakReference<EventSubscriber>> subscriberMap =
-            new WeakHashMap<MBeanServerConnection, WeakReference<EventSubscriber>>();
-}