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1   /*
2    * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
3    *
4    * This software is open source.
5    * See the bottom of this file for the licence.
6    */
7   
8   package org.dom4j.tree;
9   
10  import org.dom4j.Element;
11  import org.dom4j.Node;
12  
13  /***
14   * <p>
15   * <code>FlyweightEntity</code> is a Flyweight pattern implementation of a
16   * singly linked, read-only XML entity.
17   * </p>
18   * 
19   * <p>
20   * This node could be shared across documents and elements though it does not
21   * support the parent relationship.
22   * </p>
23   * 
24   * <p>
25   * Often this node needs to be created and then the text content added later
26   * (for example in SAX) so this implementation allows a call to {@link#setText}
27   * providing the entity has no text already.
28   * </p>
29   * 
30   * @author <a href="mailto:jstrachan@apache.org">James Strachan </a>
31   * @version $Revision: 1.6 $
32   */
33  public class FlyweightEntity extends AbstractEntity {
34      /*** The name of the <code>Entity</code> */
35      protected String name;
36  
37      /*** The text of the <code>Entity</code> */
38      protected String text;
39  
40      /***
41       * A default constructor for implementors to use.
42       */
43      protected FlyweightEntity() {
44      }
45  
46      /***
47       * Creates the <code>Entity</code> with the specified name
48       * 
49       * @param name
50       *            is the name of the entity
51       */
52      public FlyweightEntity(String name) {
53          this.name = name;
54      }
55  
56      /***
57       * Creates the <code>Entity</code> with the specified name and text.
58       * 
59       * @param name
60       *            is the name of the entity
61       * @param text
62       *            is the text of the entity
63       */
64      public FlyweightEntity(String name, String text) {
65          this.name = name;
66          this.text = text;
67      }
68  
69      /***
70       * DOCUMENT ME!
71       * 
72       * @return the name of the entity
73       */
74      public String getName() {
75          return name;
76      }
77  
78      /***
79       * DOCUMENT ME!
80       * 
81       * @return the text of the entity
82       */
83      public String getText() {
84          return text;
85      }
86  
87      /***
88       * sets the value of the entity if it is not defined yet otherwise an
89       * <code>UnsupportedOperationException</code> is thrown as this class is
90       * read only.
91       * 
92       * @param text
93       *            DOCUMENT ME!
94       * 
95       * @throws UnsupportedOperationException
96       *             DOCUMENT ME!
97       */
98      public void setText(String text) {
99          if (this.text != null) {
100             this.text = text;
101         } else {
102             throw new UnsupportedOperationException(
103                     "This Entity is read-only. " + "It cannot be modified");
104         }
105     }
106 
107     protected Node createXPathResult(Element parent) {
108         return new DefaultEntity(parent, getName(), getText());
109     }
110 }
111 
112 /*
113  * Redistribution and use of this software and associated documentation
114  * ("Software"), with or without modification, are permitted provided that the
115  * following conditions are met:
116  * 
117  * 1. Redistributions of source code must retain copyright statements and
118  * notices. Redistributions must also contain a copy of this document.
119  * 
120  * 2. Redistributions in binary form must reproduce the above copyright notice,
121  * this list of conditions and the following disclaimer in the documentation
122  * and/or other materials provided with the distribution.
123  * 
124  * 3. The name "DOM4J" must not be used to endorse or promote products derived
125  * from this Software without prior written permission of MetaStuff, Ltd. For
126  * written permission, please contact dom4j-info@metastuff.com.
127  * 
128  * 4. Products derived from this Software may not be called "DOM4J" nor may
129  * "DOM4J" appear in their names without prior written permission of MetaStuff,
130  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
131  * 
132  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
133  * 
134  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
135  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
136  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
137  * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
138  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
139  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
140  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
141  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
142  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
143  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
144  * POSSIBILITY OF SUCH DAMAGE.
145  * 
146  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
147  */