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	/*
	* 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 constant
	public 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();
	}
	}
	}

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