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1   /*
2    * Copyright 2001-2004 (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    * $Id: FlyweightEntity.java,v 1.4 2004/06/25 08:03:41 maartenc Exp $
8    */
9   
10  package org.dom4j.tree;
11  
12  import org.dom4j.Element;
13  import org.dom4j.Node;
14  
15  /*** <p><code>FlyweightEntity</code> is a Flyweight pattern implementation
16    * of a singly linked, read-only XML entity.</p>
17    *
18    * <p>This node could be shared across documents and elements though 
19    * it does not support the parent relationship.</p>
20    *
21    * <p>Often this node needs to be created and then the text content added
22    * later (for example in SAX) so this implementation allows a call to 
23    * {@link #setText} providing the entity has no text already.
24    *
25    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
26    * @version $Revision: 1.4 $
27    */
28  public class FlyweightEntity extends AbstractEntity {
29  
30      /*** The name of the <code>Entity</code> */
31      protected String name;
32  
33      /*** The text of the <code>Entity</code> */
34      protected String text;
35  
36      /*** A default constructor for implementors to use.
37        */
38      protected FlyweightEntity() {
39      }
40  
41      /*** Creates the <code>Entity</code> with the specified name
42        *
43        * @param name is the name of the entity
44        */
45      public FlyweightEntity(String name) {
46          this.name = name;
47      }
48  
49      /*** Creates the <code>Entity</code> with the specified name
50        * and text.
51        *
52        * @param name is the name of the entity
53        * @param text is the text of the entity
54        */
55      public FlyweightEntity(String name,String text) {
56          this.name = name;
57          this.text = text;
58      }
59  
60      /*** @return the name of the entity
61        */
62      public String getName() {
63          return name;
64      }
65  
66      /*** @return the text of the entity
67        */
68      public String getText() {
69          return text;
70      }
71      
72      /*** sets the value of the entity if it is not defined yet
73        * otherwise an <code>UnsupportedOperationException</code> is thrown
74        * as this class is read only.
75        */
76      public void setText(String text) {
77          if (this.text != null) {
78              this.text = text;
79          }
80          else {
81              throw new UnsupportedOperationException( 
82                  "This Entity is read-only. It cannot be modified" 
83              );
84          }
85      }
86      
87      protected Node createXPathResult(Element parent) {
88          return new DefaultEntity( parent, getName(), getText() );
89      }
90  }
91  
92  
93  
94  
95  /*
96   * Redistribution and use of this software and associated documentation
97   * ("Software"), with or without modification, are permitted provided
98   * that the following conditions are met:
99   *
100  * 1. Redistributions of source code must retain copyright
101  *    statements and notices.  Redistributions must also contain a
102  *    copy of this document.
103  *
104  * 2. Redistributions in binary form must reproduce the
105  *    above copyright notice, this list of conditions and the
106  *    following disclaimer in the documentation and/or other
107  *    materials provided with the distribution.
108  *
109  * 3. The name "DOM4J" must not be used to endorse or promote
110  *    products derived from this Software without prior written
111  *    permission of MetaStuff, Ltd.  For written permission,
112  *    please contact dom4j-info@metastuff.com.
113  *
114  * 4. Products derived from this Software may not be called "DOM4J"
115  *    nor may "DOM4J" appear in their names without prior written
116  *    permission of MetaStuff, Ltd. DOM4J is a registered
117  *    trademark of MetaStuff, Ltd.
118  *
119  * 5. Due credit should be given to the DOM4J Project - 
120  *    http://www.dom4j.org
121  *
122  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS
123  * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
124  * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
125  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
126  * METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
127  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
128  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
129  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
130  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
131  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
132  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
133  * OF THE POSSIBILITY OF SUCH DAMAGE.
134  *
135  * Copyright 2001-2004 (C) MetaStuff, Ltd. All Rights Reserved.
136  *
137  * $Id: FlyweightEntity.java,v 1.4 2004/06/25 08:03:41 maartenc Exp $
138  */