View Javadoc

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: BeanDocumentFactory.java,v 1.12 2004/06/25 08:03:33 maartenc Exp $
8    */
9   
10  package org.dom4j.bean;
11  
12  import org.dom4j.Attribute;
13  import org.dom4j.DocumentFactory;
14  import org.dom4j.Element;
15  import org.dom4j.QName;
16  import org.dom4j.tree.DefaultAttribute;
17  import org.xml.sax.Attributes;
18  
19  /*** <p><code>BeanDocumentFactory</code> is a factory of DOM4J objects
20    * which may be BeanElements which are backed by JavaBeans 
21    * and their properties. </p>
22    *
23    * <p>The tree built allows full XPath expressions from anywhere on the 
24    * tree.</p>
25    *
26    * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
27    * @version $Revision: 1.12 $
28    */
29  public class BeanDocumentFactory extends DocumentFactory {
30  
31      /*** The Singleton instance */
32      private static BeanDocumentFactory singleton = new BeanDocumentFactory();
33  
34      /*** <p>Access to the singleton instance of this factory.</p>
35        *
36        * @return the default singleon instance
37        */
38      public static DocumentFactory getInstance() {
39          return singleton;
40      }
41      
42      
43      // Factory methods
44      
45      public Element createElement(QName qname) {
46          Object bean = createBean( qname );
47          if ( bean == null ) {
48              return new BeanElement(qname);
49          }
50          else {
51              return new BeanElement(qname, bean);
52          }
53      }
54      
55      public Element createElement(QName qname, Attributes attributes) {
56          Object bean = createBean( qname, attributes );
57          if ( bean == null ) {
58              return new BeanElement(qname);
59          }
60          else {
61              return new BeanElement(qname, bean);
62          }
63      }
64      
65      public Attribute createAttribute(Element owner, QName qname, String value) {
66          return new DefaultAttribute(qname, value);
67      }
68      
69      
70      // Implementation methods
71      
72      protected Object createBean( QName qname ) {
73          return null;
74      }
75      
76      protected Object createBean( QName qname, Attributes attributes ) {
77          String value = attributes.getValue( "class" );
78          if ( value != null ) {
79              try {
80                  Class beanClass = Class.forName( 
81                      value, 
82                      true, 
83                      BeanDocumentFactory.class.getClassLoader() 
84                  );
85                  return beanClass.newInstance();
86              }
87              catch (Exception e) {
88                  handleException(e);
89              }
90          }
91          return null;
92      }
93      
94      protected void handleException(Exception e) {
95          // ignore introspection exceptions
96          System.out.println( "#### Warning: couldn't create bean: " + e );
97      }
98  }
99  
100 
101 
102 
103 /*
104  * Redistribution and use of this software and associated documentation
105  * ("Software"), with or without modification, are permitted provided
106  * that the following conditions are met:
107  *
108  * 1. Redistributions of source code must retain copyright
109  *    statements and notices.  Redistributions must also contain a
110  *    copy of this document.
111  *
112  * 2. Redistributions in binary form must reproduce the
113  *    above copyright notice, this list of conditions and the
114  *    following disclaimer in the documentation and/or other
115  *    materials provided with the distribution.
116  *
117  * 3. The name "DOM4J" must not be used to endorse or promote
118  *    products derived from this Software without prior written
119  *    permission of MetaStuff, Ltd.  For written permission,
120  *    please contact dom4j-info@metastuff.com.
121  *
122  * 4. Products derived from this Software may not be called "DOM4J"
123  *    nor may "DOM4J" appear in their names without prior written
124  *    permission of MetaStuff, Ltd. DOM4J is a registered
125  *    trademark of MetaStuff, Ltd.
126  *
127  * 5. Due credit should be given to the DOM4J Project - 
128  *    http://www.dom4j.org
129  *
130  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS
131  * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
132  * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
133  * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
134  * METASTUFF, LTD. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
135  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
136  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
137  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
138  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
139  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
140  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
141  * OF THE POSSIBILITY OF SUCH DAMAGE.
142  *
143  * Copyright 2001-2004 (C) MetaStuff, Ltd. All Rights Reserved.
144  *
145  * $Id: BeanDocumentFactory.java,v 1.12 2004/06/25 08:03:33 maartenc Exp $
146  */