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         super(WombatMBean.class);

    72         final Random r = new Random();

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

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

    75     }

    76 

    77     /**

    78      * Next are the methods to compute MBeanInfo.

    79      * You shouldn't update these methods.

    80      */

    81     @Override

    82     protected String getDescription(MBeanInfo info) {

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

    84                 "and in some computer programms.";

    85     }

    86 

    87     @Override

    88     protected String getDescription(MBeanAttributeInfo info) {

    89         String description = null;

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

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

    92         }

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

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

    95                       " -100 means that this wombat is very angry.";

    96         }

    97         return description;

    98     }

    99 

   100     @Override

   101     protected String getDescription(MBeanOperationInfo op,

   102             MBeanParameterInfo param,

   103             int sequence) {

   104         return null;

   105     }

   106 

   107     @Override

   108     protected String getParameterName(MBeanOperationInfo op,

   109             MBeanParameterInfo param,

   110             int sequence) {

   111         return null;

   112     }

   113 

   114     @Override

   115     protected String getDescription(MBeanOperationInfo info) {

   116         String description = null;

   117         return description;

   118     }

   119 

   120     @Override

   121     public MBeanInfo getMBeanInfo() {

   122         MBeanInfo mbinfo = super.getMBeanInfo();

   123         return new MBeanInfo(mbinfo.getClassName(),

   124                 mbinfo.getDescription(),

   125                 mbinfo.getAttributes(),

   126                 mbinfo.getConstructors(),

   127                 mbinfo.getOperations(),

   128                 getNotificationInfo());

   129     }

   130 

   131     /**

   132      * Get A simple caption to describe a wombat

   133      */

   134     public synchronized String getCaption() {

   135         return caption;

   136     }

   137 

   138     /**

   139      * Set A simple caption to describe a wombat

   140      */

   141     public void setCaption(String value) {

   142         final String oldValue;

   143         synchronized (this) {

   144             oldValue = caption;

   145             caption = value;

   146         }

   147         final AttributeChangeNotification notif =

   148                 new AttributeChangeNotification(objectName,

   149                     getNextSeqNumber(),

   150                     System.currentTimeMillis(),

   151                     "Caption changed","Caption",

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

   153         broadcaster.sendNotification(notif);

   154     }

   155 

   156     /**

   157      * MBeanNotification support

   158      * You shouldn't update these methods

   159      */

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

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

   162     }

   163 

   164     public MBeanNotificationInfo[] getNotificationInfo() {

   165         return new MBeanNotificationInfo[] {

   166             new MBeanNotificationInfo(new String[] {

   167                 AttributeChangeNotification.ATTRIBUTE_CHANGE},

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

   169                 "Sent when the caption changes")

   170             };

   171     }

   172 

   173     public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException {

   174         broadcaster.removeNotificationListener(listener);

   175     }

   176 

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

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

   179     }

   180 

   181     private synchronized long getNextSeqNumber() {

   182         return seqNumber++;

   183     }

   184 

   185     private long seqNumber;

   186 

   187     private final NotificationBroadcasterSupport broadcaster = new NotificationBroadcasterSupport();

   188 

   189     /**

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

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

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

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

   194      * MBean server.

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

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

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

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

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

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

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

   202      * but not necessarily be the returned value.

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

   204      * re-thrown as an MBeanRegistrationException.

   205      */

   206     @Override

   207     public ObjectName preRegister(MBeanServer server, ObjectName name)

   208             throws Exception {

   209         objectName = name;

   210         mbeanServer = server;

   211         return super.preRegister(server, name);

   212     }

   213 

   214     /**

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

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

   217      * failed.

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

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

   220      * that the registration has failed.

   221      */

   222     @Override

   223     public void postRegister(Boolean registrationDone) {

   224         super.postRegister(registrationDone);

   225     }

   226 

   227     /**

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

   229      * unregistered by the MBean server.

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

   231      * re-thrown as an MBeanRegistrationException.

   232      */

   233     @Override

   234     public void preDeregister() throws Exception {

   235         super.preDeregister();

   236     }

   237 

   238     /**

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

   240      * unregistered in the MBean server.

   241      */

   242     @Override

   243     public void postDeregister() {

   244         super.postDeregister();

   245     }

   246 

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

   248         return mbeanServer.queryNames(pattern, null);

   249     }

   250 

   251     private MBeanServer mbeanServer;

   252 

   253     private ObjectName objectName;

   254 }