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      1 /* Licensed to the Apache Software Foundation (ASF) under one or more
      2  * contributor license agreements.  See the NOTICE file distributed with
      3  * this work for additional information regarding copyright ownership.
      4  * The ASF licenses this file to You under the Apache License, Version 2.0
      5  * (the "License"); you may not use this file except in compliance with
      6  * the License.  You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package java.util.prefs;
     18 
     19 import java.io.IOException;
     20 import java.io.NotSerializableException;
     21 import java.io.ObjectInputStream;
     22 import java.io.ObjectOutputStream;
     23 import java.io.Serializable;
     24 import java.util.EventObject;
     25 
     26 /**
     27  * This is the event class to indicate that one child of the preference node has
     28  * been added or deleted.
     29  * <p>
     30  * Please note that although the class is marked as {@code Serializable} by
     31  * inheritance from {@code EventObject}, this type is not intended to be serialized
     32  * so the serialization methods do nothing but throw a {@code NotSerializableException}.
     33  *
     34  * @see java.util.prefs.Preferences
     35  * @see java.util.prefs.NodeChangeListener
     36  *
     37  * @since 1.4
     38  */
     39 public class NodeChangeEvent extends EventObject implements Serializable {
     40 
     41     private static final long serialVersionUID = 8068949086596572957L;
     42 
     43     private final Preferences parent;
     44     private final Preferences child;
     45 
     46     /**
     47      * Constructs a new {@code NodeChangeEvent} instance.
     48      *
     49      * @param p
     50      *            the {@code Preferences} instance that fired this event; this object is
     51      *            considered as the event source.
     52      * @param c
     53      *            the child {@code Preferences} instance that was added or deleted.
     54      */
     55     public NodeChangeEvent (Preferences p, Preferences c) {
     56         super(p);
     57         parent = p;
     58         child = c;
     59     }
     60 
     61     /**
     62      * Gets the {@code Preferences} instance that fired this event.
     63      *
     64      * @return the {@code Preferences} instance that fired this event.
     65      */
     66     public Preferences getParent() {
     67         return parent;
     68     }
     69 
     70     /**
     71      * Gets the child {@code Preferences} node that was added or removed.
     72      *
     73      * @return the added or removed child {@code Preferences} node.
     74      */
     75     public Preferences getChild() {
     76         return child;
     77     }
     78 
     79     /**
     80      * This method always throws a <code>NotSerializableException</code>,
     81      * because this object cannot be serialized,
     82      */
     83     private void writeObject (ObjectOutputStream out) throws IOException {
     84         throw new NotSerializableException();
     85     }
     86 
     87     /**
     88      * This method always throws a <code>NotSerializableException</code>,
     89      * because this object cannot be serialized,
     90      */
     91     private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
     92         throw new NotSerializableException();
     93     }
     94 }
     95