001 /*
002 * Copyright 2000-2003 Sun Microsystems, Inc. All Rights Reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation. Sun designates this
008 * particular file as subject to the "Classpath" exception as provided
009 * by Sun in the LICENSE file that accompanied this code.
010 *
011 * This code is distributed in the hope that it will be useful, but WITHOUT
012 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014 * version 2 for more details (a copy is included in the LICENSE file that
015 * accompanied this code).
016 *
017 * You should have received a copy of the GNU General Public License version
018 * 2 along with this work; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020 *
021 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022 * CA 95054 USA or visit www.sun.com if you need additional information or
023 * have any questions.
024 */
025
026 package java.util.prefs;
027
028 import java.io.NotSerializableException;
029
030 /**
031 * An event emitted by a <tt>Preferences</tt> node to indicate that
032 * a preference has been added, removed or has had its value changed.<p>
033 *
034 * Note, that although PreferenceChangeEvent inherits Serializable interface
035 * from EventObject, it is not intended to be Serializable. Appropriate
036 * serialization methods are implemented to throw NotSerializableException.
037 *
038 * @author Josh Bloch
039 * @version 1.13, 05/05/07
040 * @see Preferences
041 * @see PreferenceChangeListener
042 * @see NodeChangeEvent
043 * @since 1.4
044 * @serial exclude
045 */
046 public class PreferenceChangeEvent extends java.util.EventObject {
047
048 /**
049 * Key of the preference that changed.
050 *
051 * @serial
052 */
053 private String key;
054
055 /**
056 * New value for preference, or <tt>null</tt> if it was removed.
057 *
058 * @serial
059 */
060 private String newValue;
061
062 /**
063 * Constructs a new <code>PreferenceChangeEvent</code> instance.
064 *
065 * @param node The Preferences node that emitted the event.
066 * @param key The key of the preference that was changed.
067 * @param newValue The new value of the preference, or <tt>null</tt>
068 * if the preference is being removed.
069 */
070 public PreferenceChangeEvent(Preferences node, String key,
071 String newValue) {
072 super (node);
073 this .key = key;
074 this .newValue = newValue;
075 }
076
077 /**
078 * Returns the preference node that emitted the event.
079 *
080 * @return The preference node that emitted the event.
081 */
082 public Preferences getNode() {
083 return (Preferences) getSource();
084 }
085
086 /**
087 * Returns the key of the preference that was changed.
088 *
089 * @return The key of the preference that was changed.
090 */
091 public String getKey() {
092 return key;
093 }
094
095 /**
096 * Returns the new value for the preference.
097 *
098 * @return The new value for the preference, or <tt>null</tt> if the
099 * preference was removed.
100 */
101 public String getNewValue() {
102 return newValue;
103 }
104
105 /**
106 * Throws NotSerializableException, since NodeChangeEvent objects
107 * are not intended to be serializable.
108 */
109 private void writeObject(java.io.ObjectOutputStream out)
110 throws NotSerializableException {
111 throw new NotSerializableException("Not serializable.");
112 }
113
114 /**
115 * Throws NotSerializableException, since PreferenceChangeEvent objects
116 * are not intended to be serializable.
117 */
118 private void readObject(java.io.ObjectInputStream in)
119 throws NotSerializableException {
120 throw new NotSerializableException("Not serializable.");
121 }
122
123 // Defined so that this class isn't flagged as a potential problem when
124 // searches for missing serialVersionUID fields are done.
125 private static final long serialVersionUID = 793724513368024975L;
126 }
|