/* * Copyright (c) 1999, 2008, 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 javax.management; import java.io.IOException;import java.io.ObjectInputStream;import java.io.ObjectOutputStream;import java.io.ObjectStreamField;import java.util.EventObject; import java.security.AccessController; import com.sun.jmx.mbeanserver.GetPropertyAction; /** * <p>The Notification class represents a notification emitted by an * MBean.  It contains a reference to the source MBean: if the * notification has been forwarded through the MBean server, and the * original source of the notification was a reference to the emitting * MBean object, then the MBean server replaces it by the MBean's * ObjectName.  If the listener has registered directly with the * MBean, this is either the object name or a direct reference to the * MBean.</p> * * <p>It is strongly recommended that notification senders use the * object name rather than a reference to the MBean object as the * source.</p> * * <p>The <b>serialVersionUID</b> of this class is <code>-7516092053498031989L</code>. * * @since 1.5 */@SuppressWarnings("serial")  // serialVersionUID is not constantpublic class Notification extends EventObject {     // Serialization compatibility stuff:    // Two serial forms are supported in this class. The selected form depends    // on system property "jmx.serial.form":    //  - "1.0" for JMX 1.0    //  - any other value for JMX 1.1 and higher    //    // Serial version for old serial form    private static final long oldSerialVersionUID = 1716977971058914352L;    //    // Serial version for new serial form    private static final long newSerialVersionUID = -7516092053498031989L;    //    // Serializable fields in old serial form    private static final ObjectStreamField[] oldSerialPersistentFields =    {        new ObjectStreamField("message", String.class),        new ObjectStreamField("sequenceNumber", Long.TYPE),        new ObjectStreamField("source", Object.class),        new ObjectStreamField("sourceObjectName", ObjectName.class),        new ObjectStreamField("timeStamp", Long.TYPE),        new ObjectStreamField("type", String.class),        new ObjectStreamField("userData", Object.class)    };    //    // Serializable fields in new serial form    private static final ObjectStreamField[] newSerialPersistentFields =    {        new ObjectStreamField("message", String.class),        new ObjectStreamField("sequenceNumber", Long.TYPE),        new ObjectStreamField("source", Object.class),        new ObjectStreamField("timeStamp", Long.TYPE),        new ObjectStreamField("type", String.class),        new ObjectStreamField("userData", Object.class)    };    //    // Actual serial version and serial form    private static final long serialVersionUID;    /**     * @serialField type String The notification type.     *              A string expressed in a dot notation similar to Java properties.     *              An example of a notification type is network.alarm.router     * @serialField sequenceNumber long The notification sequence number.     *              A serial number which identify particular instance     *              of notification in the context of the notification source.     * @serialField timeStamp long The notification timestamp.     *              Indicating when the notification was generated     * @serialField userData Object The notification user data.     *              Used for whatever other data the notification     *              source wishes to communicate to its consumers     * @serialField message String The notification message.     * @serialField source Object The object on which the notification initially occurred.     */    private static final ObjectStreamField[] serialPersistentFields;    private static boolean compat = false;    static {        try {            GetPropertyAction act = new GetPropertyAction("jmx.serial.form");            String form = AccessController.doPrivileged(act);            compat = (form != null && form.equals("1.0"));        } catch (Exception e) {            // OK: exception means no compat with 1.0, too bad        }        if (compat) {            serialPersistentFields = oldSerialPersistentFields;            serialVersionUID = oldSerialVersionUID;        } else {            serialPersistentFields = newSerialPersistentFields;            serialVersionUID = newSerialVersionUID;        }    }    //    // END Serialization compatibility stuff     /**     * @serial The notification type.     *         A string expressed in a dot notation similar to Java properties.     *         An example of a notification type is network.alarm.router     */    private String type;     /**     * @serial The notification sequence number.     *         A serial number which identify particular instance     *         of notification in the context of the notification source.     */    private long sequenceNumber;     /**     * @serial The notification timestamp.     *         Indicating when the notification was generated     */    private long timeStamp;     /**     * @serial The notification user data.     *         Used for whatever other data the notification     *         source wishes to communicate to its consumers     */    private Object userData = null;     /**     * @serial The notification message.     */    private String message  = "";     /**     * <p>This field hides the {@link EventObject#source} field in the     * parent class to make it non-transient and therefore part of the     * serialized form.</p>     *     * @serial The object on which the notification initially occurred.     */    protected Object source = null;      /**     * Creates a Notification object.     * The notification timeStamp is set to the current date.     *     * @param type The notification type.     * @param source The notification source.     * @param sequenceNumber The notification sequence number within the source object.     *     */    public Notification(String type, Object source, long sequenceNumber) {        super (source) ;        this.source = source;        this.type = type;        this.sequenceNumber = sequenceNumber ;        this.timeStamp = (new java.util.Date()).getTime() ;    }     /**     * Creates a Notification object.     * The notification timeStamp is set to the current date.     *     * @param type The notification type.     * @param source The notification source.     * @param sequenceNumber The notification sequence number within the source object.     * @param message The detailed message.     *     */    public Notification(String type, Object source, long sequenceNumber, String message) {        super (source) ;        this.source = source;        this.type = type;        this.sequenceNumber = sequenceNumber ;        this.timeStamp = (new java.util.Date()).getTime() ;        this.message = message ;    }     /**     * Creates a Notification object.     *     * @param type The notification type.     * @param source The notification source.     * @param sequenceNumber The notification sequence number within the source object.     * @param timeStamp The notification emission date.     *     */    public Notification(String type, Object source, long sequenceNumber, long timeStamp) {        super (source) ;        this.source = source;        this.type = type ;        this.sequenceNumber = sequenceNumber ;        this.timeStamp = timeStamp ;    }     /**     * Creates a Notification object.     *     * @param type The notification type.     * @param source The notification source.     * @param sequenceNumber The notification sequence number within the source object.     * @param timeStamp The notification emission date.     * @param message The detailed message.     *     */    public Notification(String type, Object source, long sequenceNumber, long timeStamp, String message) {        super (source) ;        this.source = source;        this.type = type ;        this.sequenceNumber = sequenceNumber ;        this.timeStamp = timeStamp ;        this.message = message ;    }     /**     * Sets the source.     *     * @param source the new source for this object.     *     * @see EventObject#getSource     */    public void setSource(Object source) {        super.source = source;        this.source = source;    }     /**     * Get the notification sequence number.     *     * @return The notification sequence number within the source object. It's a serial number     * identifying a particular instance of notification in the context of the notification source.     * The notification model does not assume that notifications will be received in the same order     * that they are sent. The sequence number helps listeners to sort received notifications.     *     * @see #setSequenceNumber     */    public long getSequenceNumber() {        return sequenceNumber ;    }     /**     * Set the notification sequence number.     *     * @param sequenceNumber The notification sequence number within the source object. It is     * a serial number identifying a particular instance of notification in the     * context of the notification source.     *     * @see #getSequenceNumber     */    public void setSequenceNumber(long sequenceNumber) {        this.sequenceNumber = sequenceNumber;    }     /**     * Get the notification type.     *     * @return The notification type. It's a string expressed in a dot notation     * similar to Java properties. It is recommended that the notification type     * should follow the reverse-domain-name convention used by Java package     * names.  An example of a notification type is com.example.alarm.router.     */    public String getType() {        return type ;    }     /**     * Get the notification timestamp.     *     * @return The notification timestamp.     *     * @see #setTimeStamp     */    public long getTimeStamp() {        return timeStamp ;    }     /**     * Set the notification timestamp.     *     * @param timeStamp The notification timestamp. It indicates when the notification was generated.     *     * @see #getTimeStamp     */    public void setTimeStamp(long timeStamp) {        this.timeStamp = timeStamp;    }     /**     * Get the notification message.     *     * @return The message string of this notification object.     *     */    public String getMessage() {        return message ;    }     /**     * Get the user data.     *     * @return The user data object. It is used for whatever data     * the notification source wishes to communicate to its consumers.     *     * @see #setUserData     */    public Object getUserData() {        return userData ;    }     /**     * Set the user data.     *     * @param userData The user data object. It is used for whatever data     * the notification source wishes to communicate to its consumers.     *     * @see #getUserData     */    public void setUserData(Object userData) {         this.userData = userData ;    }     /**     * Returns a String representation of this notification.     *     * @return A String representation of this notification.     */    @Override    public String toString() {        return super.toString()+"[type="+type+"][message="+message+"]";    }     /**     * Deserializes a {@link Notification} from an {@link ObjectInputStream}.     */    private void readObject(ObjectInputStream in)            throws IOException, ClassNotFoundException {      // New serial form ignores extra field "sourceObjectName"      in.defaultReadObject();      super.source = source;    }      /**     * Serializes a {@link Notification} to an {@link ObjectOutputStream}.     */    private void writeObject(ObjectOutputStream out)            throws IOException {        if (compat) {            // Serializes this instance in the old serial form            //            ObjectOutputStream.PutField fields = out.putFields();            fields.put("type", type);            fields.put("sequenceNumber", sequenceNumber);            fields.put("timeStamp", timeStamp);            fields.put("userData", userData);            fields.put("message", message);            fields.put("source", source);            out.writeFields();        } else {            // Serializes this instance in the new serial form            //            out.defaultWriteObject();        }    }}