1 /*

     2  * Copyright 2007-2008 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package javax.management.event;

    27 

    28 import com.sun.jmx.remote.util.ClassLogger;

    29 import java.io.IOException;

    30 import java.rmi.NoSuchObjectException;

    31 import java.rmi.RemoteException;

    32 import java.rmi.server.UnicastRemoteObject;

    33 import java.rmi.server.RMIClientSocketFactory;

    34 import java.rmi.server.RMIServerSocketFactory;

    35 import javax.management.MBeanException;

    36 import javax.management.remote.NotificationResult;

    37 

    38 /**

    39  * This class is an implementation of the {@link EventRelay} interface, using

    40  * push mode. It exports an RMI object that {@link RMIPushEventForwarder} uses

    41  * to forward notifications.

    42  *

    43  * @since JMX 2.0

    44  */

    45 public class RMIPushEventRelay implements EventRelay {

    46     /**

    47      * Constructs a default {@code RMIPushEventRelay} object

    48      * and exports its {@linkplain RMIPushServer notification

    49      * receiver} on any free port. This constructor is equivalent

    50      * to {@link #RMIPushEventRelay(EventClientDelegateMBean,

    51      * int, RMIClientSocketFactory, RMIServerSocketFactory, int)

    52      * RMIPushEventRelay(delegate, 0, null, null, <em>&lt;default buffer

    53      * size&gt;</em>)}.

    54      *

    55      * @param delegate The {@link EventClientDelegateMBean} proxy to work with.

    56      * @throws IOException if failed to communicate with

    57      * {@link EventClientDelegateMBean}.

    58      * @throws MBeanException if the {@link EventClientDelegateMBean} failed

    59      * to create an {@code EventForwarder} for this object.

    60      */

    61     public RMIPushEventRelay(EventClientDelegateMBean delegate)

    62     throws IOException, MBeanException {

    63         this(delegate, 0, null,  null, 0);

    64     }

    65 

    66     /**

    67      * Constructs a {@code RMIPushEventRelay} object and exports its

    68      * {@linkplain RMIPushServer notification receiver} on a specified port.

    69      *

    70      * @param delegate The {@link EventClientDelegateMBean} proxy to work with.

    71      * @param port The port used to export an RMI object to receive notifications

    72      * from a server. If the port is zero, an anonymous port is used.

    73      * @param csf The client socket factory used to export the RMI object.

    74      * Can be null.

    75      * @param ssf The server socket factory used to export the RMI object.

    76      * Can be null.

    77      * @param bufferSize The number of notifications held on the server

    78      * while waiting for the previous transmission to complete.  A value of

    79      * zero means the default buffer size.

    80      *

    81      * @throws IOException if failed to communicate with

    82      * {@link EventClientDelegateMBean}.

    83      * @throws MBeanException if the {@link EventClientDelegateMBean} failed

    84      * to create an {@code EventForwarder} for this object.

    85      *

    86      * @see RMIPushEventForwarder#RMIPushEventForwarder(RMIPushServer, int)

    87      */

    88     public RMIPushEventRelay(EventClientDelegateMBean delegate,

    89             int port,

    90             RMIClientSocketFactory csf,

    91             RMIServerSocketFactory ssf,

    92             int bufferSize)

    93             throws IOException, MBeanException {

    94 

    95         UnicastRemoteObject.exportObject(exportedReceiver, port, csf, ssf);

    96 

    97         clientId = delegate.addClient(

    98                 RMIPushEventForwarder.class.getName(),

    99                 new Object[] {exportedReceiver, bufferSize},

   100                 new String[] {RMIPushServer.class.getName(),

   101                               int.class.getName()});

   102     }

   103 

   104     public String getClientId() {

   105         return clientId;

   106     }

   107 

   108     public void setEventReceiver(EventReceiver receiver) {

   109         if (logger.traceOn()) {

   110             logger.trace("setEventReceiver", ""+receiver);

   111         }

   112         synchronized(lock) {

   113             this.receiver = receiver;

   114         }

   115     }

   116 

   117     public void stop() {

   118         if (logger.traceOn()) {

   119             logger.trace("stop", "");

   120         }

   121         synchronized(lock) {

   122             if (stopped) {

   123                 return;

   124             } else {

   125                 stopped = true;

   126             }

   127 

   128             if (clientId == null) {

   129                 return;

   130             }

   131 

   132             try {

   133                 UnicastRemoteObject.unexportObject(exportedReceiver, true);

   134             } catch (NoSuchObjectException nsoe) {

   135                 logger.fine("RMIPushEventRelay.stop", "unexport", nsoe);

   136                 // OK: we wanted it unexported, and apparently it already is

   137             }

   138         }

   139     }

   140 

   141     private volatile String clientId;

   142     private volatile EventReceiver receiver;

   143 

   144     private RMIPushServer exportedReceiver = new RMIPushServer() {

   145         public void receive(NotificationResult nr) throws RemoteException {

   146             if (logger.traceOn()) {

   147                 logger.trace("EventPusherImpl-receive","");

   148             }

   149             receiver.receive(nr);

   150             // Any exception will be sent back to the client.

   151         }

   152     };

   153 

   154     private boolean stopped = false;

   155 

   156     private final int[] lock = new int[0];

   157 

   158     private static final ClassLogger logger =

   159             new ClassLogger("javax.management.event",

   160             "PushEventRelay");

   161 }