/*
* 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();
}
}
}