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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.io;
9   
10  import java.io.IOException;
11  
12  import org.dom4j.Document;
13  
14  import org.xml.sax.ContentHandler;
15  import org.xml.sax.ErrorHandler;
16  import org.xml.sax.SAXException;
17  import org.xml.sax.XMLReader;
18  import org.xml.sax.helpers.DefaultHandler;
19  
20  /***
21   * <p>
22   * <code>SAXValidator</code> validates an XML document by writing the document
23   * to a text buffer and parsing it with a validating SAX parser. This could be
24   * implemented much more efficiently by validating against the dom4j object
25   * model directly but at least allows the reuse of existing SAX based validating
26   * parsers.
27   * </p>
28   * 
29   * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
30   * @version $Revision: 1.10 $
31   */
32  public class SAXValidator {
33      /*** <code>XMLReader</code> used to parse the SAX events */
34      private XMLReader xmlReader;
35  
36      /*** ErrorHandler class to use */
37      private ErrorHandler errorHandler;
38  
39      public SAXValidator() {
40      }
41  
42      public SAXValidator(XMLReader xmlReader) {
43          this.xmlReader = xmlReader;
44      }
45  
46      /***
47       * Validates the given <code>Document</code> by writing it to a validating
48       * SAX Parser.
49       * 
50       * @param document
51       *            is the Document to validate
52       * 
53       * @throws SAXException
54       *             if a validation error occurs
55       * @throws RuntimeException
56       *             DOCUMENT ME!
57       */
58      public void validate(Document document) throws SAXException {
59          if (document != null) {
60              XMLReader reader = getXMLReader();
61  
62              if (errorHandler != null) {
63                  reader.setErrorHandler(errorHandler);
64              }
65  
66              try {
67                  reader.parse(new DocumentInputSource(document));
68              } catch (IOException e) {
69                  throw new RuntimeException("Caught and exception that should "
70                          + "never happen: " + e);
71              }
72          }
73      }
74  
75      // Properties
76      // -------------------------------------------------------------------------
77  
78      /***
79       * DOCUMENT ME!
80       * 
81       * @return the <code>XMLReader</code> used to parse SAX events
82       * 
83       * @throws SAXException
84       *             DOCUMENT ME!
85       */
86      public XMLReader getXMLReader() throws SAXException {
87          if (xmlReader == null) {
88              xmlReader = createXMLReader();
89              configureReader();
90          }
91  
92          return xmlReader;
93      }
94  
95      /***
96       * Sets the <code>XMLReader</code> used to parse SAX events
97       * 
98       * @param reader
99       *            is the <code>XMLReader</code> to parse SAX events
100      * 
101      * @throws SAXException
102      *             DOCUMENT ME!
103      */
104     public void setXMLReader(XMLReader reader) throws SAXException {
105         this.xmlReader = reader;
106         configureReader();
107     }
108 
109     /***
110      * DOCUMENT ME!
111      * 
112      * @return the <code>ErrorHandler</code> used by SAX
113      */
114     public ErrorHandler getErrorHandler() {
115         return errorHandler;
116     }
117 
118     /***
119      * Sets the <code>ErrorHandler</code> used by the SAX
120      * <code>XMLReader</code>.
121      * 
122      * @param errorHandler
123      *            is the <code>ErrorHandler</code> used by SAX
124      */
125     public void setErrorHandler(ErrorHandler errorHandler) {
126         this.errorHandler = errorHandler;
127     }
128 
129     // Implementation methods
130     // -------------------------------------------------------------------------
131 
132     /***
133      * Factory Method to allow alternate methods of creating and configuring
134      * XMLReader objects
135      * 
136      * @return DOCUMENT ME!
137      * 
138      * @throws SAXException
139      *             DOCUMENT ME!
140      */
141     protected XMLReader createXMLReader() throws SAXException {
142         return SAXHelper.createXMLReader(true);
143     }
144 
145     /***
146      * Configures the XMLReader before use
147      * 
148      * @throws SAXException
149      *             DOCUMENT ME!
150      */
151     protected void configureReader() throws SAXException {
152         ContentHandler handler = xmlReader.getContentHandler();
153 
154         if (handler == null) {
155             xmlReader.setContentHandler(new DefaultHandler());
156         }
157 
158         // configure validation support
159         xmlReader.setFeature("http://xml.org/sax/features/validation", true);
160 
161         // configure namespace support
162         xmlReader.setFeature("http://xml.org/sax/features/namespaces", true);
163         xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes",
164                 false);
165     }
166 }
167 
168 /*
169  * Redistribution and use of this software and associated documentation
170  * ("Software"), with or without modification, are permitted provided that the
171  * following conditions are met:
172  * 
173  * 1. Redistributions of source code must retain copyright statements and
174  * notices. Redistributions must also contain a copy of this document.
175  * 
176  * 2. Redistributions in binary form must reproduce the above copyright notice,
177  * this list of conditions and the following disclaimer in the documentation
178  * and/or other materials provided with the distribution.
179  * 
180  * 3. The name "DOM4J" must not be used to endorse or promote products derived
181  * from this Software without prior written permission of MetaStuff, Ltd. For
182  * written permission, please contact dom4j-info@metastuff.com.
183  * 
184  * 4. Products derived from this Software may not be called "DOM4J" nor may
185  * "DOM4J" appear in their names without prior written permission of MetaStuff,
186  * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
187  * 
188  * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
189  * 
190  * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
191  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
192  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
193  * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
194  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
195  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
196  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
197  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
198  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
199  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
200  * POSSIBILITY OF SUCH DAMAGE.
201  * 
202  * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
203  */