1 /*

     2  * Copyright 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.

     8  *

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

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

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

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

    13  * accompanied this code).

    14  *

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

    16  * 2 along with this work; if not, write to the Free Software Foundation,

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

    18  *

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

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

    21  * have any questions.

    22  */

    23 

    24 import java.util.Random;

    25 import java.util.Set;

    26 import javax.management.AttributeChangeNotification;

    27 import javax.management.ListenerNotFoundException;

    28 import javax.management.MBeanAttributeInfo;

    29 import javax.management.MBeanInfo;

    30 import javax.management.MBeanNotificationInfo;

    31 import javax.management.MBeanOperationInfo;

    32 import javax.management.MBeanParameterInfo;

    33 import javax.management.MBeanRegistration;

    34 import javax.management.MBeanServer;

    35 import javax.management.NotCompliantMBeanException;

    36 import javax.management.NotificationBroadcasterSupport;

    37 import javax.management.NotificationEmitter;

    38 import javax.management.NotificationFilter;

    39 import javax.management.NotificationListener;

    40 import javax.management.ObjectName;

    41 import javax.management.StandardMBean;

    42 

    43 

    44 /**

    45  * Dynamic MBean based on StandardMBean

    46  * Class Wombat

    47  * Wombat Description

    48  * @author dfuchs

    49  */

    50 public class Wombat extends StandardMBean

    51         implements WombatMBean, NotificationEmitter, MBeanRegistration {

    52 

    53     /**

    54      * Attribute : Caption

    55      */

    56     private String caption = "I'm a wombat";

    57 

    58     private final long MAX_SEED = 36000;

    59     private final long seed;

    60     private final long period;

    61     private volatile int mood = 0;

    62 

    63     public int getMood() {

    64         final long  degree = seed + (System.currentTimeMillis()/period)%MAX_SEED;

    65         final double angle = ((double)degree)/100;

    66         mood = (int)(100.0*Math.sin(angle));

    67         return mood;

    68     }

    69 

    70     public Wombat() throws NotCompliantMBeanException {

    71         this(WombatMBean.class);

    72     }

    73 

    74     public Wombat(Class<? extends WombatMBean> clazz)

    75             throws NotCompliantMBeanException {

    76         super(clazz);

    77         final Random r = new Random();

    78         seed = ((r.nextLong() % MAX_SEED) + MAX_SEED)%MAX_SEED;

    79         period = 200 + (((r.nextLong()%80)+80)%80)*10;

    80     }

    81 

    82     /**

    83      * Next are the methods to compute MBeanInfo.

    84      * You shouldn't update these methods.

    85      */

    86     @Override

    87     protected String getDescription(MBeanInfo info) {

    88         return "Wombats are strange beasts. You will find them down under " +

    89                 "and in some computer programms.";

    90     }

    91 

    92     @Override

    93     protected String getDescription(MBeanAttributeInfo info) {

    94         String description = null;

    95         if (info.getName().equals("Caption")) {

    96             description = "A simple caption to describe a wombat";

    97         }

    98         if (info.getName().equals("Mood")) {

    99             description = "This Wombat's mood on a [-100,+100] scale."+

   100                       " -100 means that this wombat is very angry.";

   101         }

   102         return description;

   103     }

   104 

   105     @Override

   106     protected String getDescription(MBeanOperationInfo op,

   107             MBeanParameterInfo param,

   108             int sequence) {

   109         return null;

   110     }

   111 

   112     @Override

   113     protected String getParameterName(MBeanOperationInfo op,

   114             MBeanParameterInfo param,

   115             int sequence) {

   116         return null;

   117     }

   118 

   119     @Override

   120     protected String getDescription(MBeanOperationInfo info) {

   121         String description = null;

   122         return description;

   123     }

   124 

   125     @Override

   126     public MBeanInfo getMBeanInfo() {

   127         MBeanInfo mbinfo = super.getMBeanInfo();

   128         return new MBeanInfo(mbinfo.getClassName(),

   129                 mbinfo.getDescription(),

   130                 mbinfo.getAttributes(),

   131                 mbinfo.getConstructors(),

   132                 mbinfo.getOperations(),

   133                 getNotificationInfo());

   134     }

   135 

   136     /**

   137      * Get A simple caption to describe a wombat

   138      */

   139     public synchronized String getCaption() {

   140         return caption;

   141     }

   142 

   143     /**

   144      * Set A simple caption to describe a wombat

   145      */

   146     public void setCaption(String value) {

   147         final String oldValue;

   148         synchronized (this) {

   149             oldValue = caption;

   150             caption = value;

   151         }

   152         final AttributeChangeNotification notif =

   153                 new AttributeChangeNotification(objectName,

   154                     getNextSeqNumber(),

   155                     System.currentTimeMillis(),

   156                     "Caption changed","Caption",

   157                     String.class.getName(),oldValue,value);

   158         broadcaster.sendNotification(notif);

   159     }

   160 

   161     /**

   162      * MBeanNotification support

   163      * You shouldn't update these methods

   164      */

   165     public void addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws IllegalArgumentException {

   166         broadcaster.addNotificationListener(listener, filter, handback);

   167     }

   168 

   169     public MBeanNotificationInfo[] getNotificationInfo() {

   170         return new MBeanNotificationInfo[] {

   171             new MBeanNotificationInfo(new String[] {

   172                 AttributeChangeNotification.ATTRIBUTE_CHANGE},

   173                 javax.management.AttributeChangeNotification.class.getName(),

   174                 "Sent when the caption changes")

   175             };

   176     }

   177 

   178     public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException {

   179         broadcaster.removeNotificationListener(listener);

   180     }

   181 

   182     public void removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws ListenerNotFoundException {

   183         broadcaster.removeNotificationListener(listener, filter, handback);

   184     }

   185 

   186     private synchronized long getNextSeqNumber() {

   187         return seqNumber++;

   188     }

   189 

   190     private long seqNumber;

   191 

   192     private final NotificationBroadcasterSupport broadcaster = new NotificationBroadcasterSupport();

   193 

   194     /**

   195      * Allows the MBean to perform any operations it needs before being

   196      * registered in the MBean server. If the name of the MBean is not

   197      * specified, the MBean can provide a name for its registration. If

   198      * any exception is raised, the MBean will not be registered in the

   199      * MBean server.

   200      * @param server The MBean server in which the MBean will be registered.

   201      * @param name The object name of the MBean. This name is null if the

   202      * name parameter to one of the createMBean or registerMBean methods in

   203      * the MBeanServer interface is null. In that case, this method must

   204      * return a non-null ObjectName for the new MBean.

   205      * @return The name under which the MBean is to be registered. This value

   206      * must not be null. If the name parameter is not null, it will usually

   207      * but not necessarily be the returned value.

   208      * @throws Exception This exception will be caught by the MBean server and

   209      * re-thrown as an MBeanRegistrationException.

   210      */

   211     @Override

   212     public ObjectName preRegister(MBeanServer server, ObjectName name)

   213             throws Exception {

   214         objectName = name;

   215         mbeanServer = server;

   216         return super.preRegister(server, name);

   217     }

   218 

   219     /**

   220      * Allows the MBean to perform any operations needed after having

   221      * been registered in the MBean server or after the registration has

   222      * failed.

   223      * @param registrationDone Indicates wether or not the MBean has been

   224      * successfully registered in the MBean server. The value false means

   225      * that the registration has failed.

   226      */

   227     @Override

   228     public void postRegister(Boolean registrationDone) {

   229         super.postRegister(registrationDone);

   230     }

   231 

   232     /**

   233      * Allows the MBean to perform any operations it needs before being

   234      * unregistered by the MBean server.

   235      * @throws Exception This exception will be caught by the MBean server and

   236      * re-thrown as an MBeanRegistrationException.

   237      */

   238     @Override

   239     public void preDeregister() throws Exception {

   240         super.preDeregister();

   241     }

   242 

   243     /**

   244      * Allows the MBean to perform any operations needed after having been

   245      * unregistered in the MBean server.

   246      */

   247     @Override

   248     public void postDeregister() {

   249         super.postDeregister();

   250     }

   251 

   252     public Set<ObjectName> listMatching(ObjectName pattern) {

   253         return mbeanServer.queryNames(pattern, null);

   254     }

   255 

   256     private MBeanServer mbeanServer;

   257 

   258     private ObjectName objectName;

   259 }