CmsXmlXercesParser


1   /*
2   * File   : $Source: /usr/local/cvs/opencms/src-modules/com/opencms/template/CmsXmlXercesParser.java,v $
3   * Date   : $Date: 2005/05/31 15:51:19 $
4   * Version: $Revision: 1.2 $
5   *
6   * This library is part of OpenCms -
7   * the Open Source Content Mananagement System
8   *
9   * Copyright (C) 2001  The OpenCms Group
10  *
11  * This library is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU Lesser General Public
13  * License as published by the Free Software Foundation; either
14  * version 2.1 of the License, or (at your option) any later version.
15  *
16  * This library is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * Lesser General Public License for more details.
20  *
21  * For further information about OpenCms, please see the
22  * OpenCms Website: http://www.opencms.org 
23  *
24  * You should have received a copy of the GNU Lesser General Public
25  * License along with this library; if not, write to the Free Software
26  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
27  */
28  
29  
30  package com.opencms.template;
31  
32  import org.opencms.main.CmsLog;
33  import org.opencms.main.OpenCms;
34  
35  import java.io.InputStream  ;
36  import java.io.OutputStream  ;
37  import java.io.Reader  ;
38  import java.io.StringReader  ;
39  import java.io.Writer  ;
40  
41  import org.apache.xerces.parsers.DOMParser;
42  import org.apache.xml.serialize.DOMSerializer;
43  import org.apache.xml.serialize.OutputFormat;
44  import org.apache.xml.serialize.XMLSerializer;
45  
46  import org.w3c.dom.Document  ;
47  import org.w3c.dom.Node  ;
48  import org.xml.sax.InputSource  ;
49  import org.xml.sax.SAXException  ;
50  
51  /**
52   * Implementation of the OpenCms XML parser interface for
53   * the Xerces parser.
54   * 
55   * @author Alexander Kandzior
56   * @author Alexander Lucas
57   * @version $Revision: 1.2 $ $Date: 2005/05/31 15:51:19 $
58   * 
59   * @deprecated Will not be supported past the OpenCms 6 release.
60   */
61  public class CmsXmlXercesParser implements I_CmsXmlParser {
62      
63      /** Prevents the parser from printing multiple error messages.*/
64      private static boolean c_xercesWarning = false;
65      
66      /**
67       * Creates an empty DOM XML document.
68       * Workaround because the original method is not working as expected.
69       * 
70       * @param docNod first Node in empty  XML document
71       * @return Empty document.
72       */
73      public Document   createEmptyDocument(String   docNod) throws Exception   {
74          String   docXml = new String  ("<?xml version=\"1.0\" encoding=\"" + OpenCms.getSystemInfo().getDefaultEncoding() + "\"?>");
75          docXml = docXml + "<" + docNod + ">" + "</" + docNod + ">";
76          StringReader   reader = new StringReader  (docXml);
77          return parse(reader);
78      }
79      
80      /**
81       * Calls a XML printer for converting a XML DOM document
82       * to a String.
83       * @param doc Document to be printed.
84       * @param out OutputStream to print to.
85       */
86      public void getXmlText(Document   doc, OutputStream   out, String   encoding) {
87          OutputFormat outf =
88              new OutputFormat(doc, (encoding == null) ? getOriginalEncoding(doc) : encoding, true);
89          outf.setLineWidth(C_XML_LINE_WIDTH);
90          outf.setPreserveSpace(false);
91          XMLSerializer serializer = new XMLSerializer(out, outf);
92          try {
93              DOMSerializer domSerializer = serializer.asDOMSerializer();
94              domSerializer.serialize(doc);
95          } catch (Exception   e) {
96              if (CmsLog.getLog(this).isErrorEnabled()) {
97                  CmsLog.getLog(this).error("Xml parsing error", e);
98              }
99          }
100     }
101 
102     /**
103      * Calls a XML printer for converting a XML DOM document
104      * to a String.
105      * @param doc Document to be printed.
106      * @param out Writer to print to.
107      * @param encoding the character encoding to be used while serializing
108      */
109     public void getXmlText(Document   doc, Writer   out, String   encoding) {
110         OutputFormat outf =
111             new OutputFormat(doc, (encoding == null) ? getOriginalEncoding(doc) : encoding, true);
112         outf.setLineWidth(C_XML_LINE_WIDTH);
113         outf.setPreserveSpace(false);
114         XMLSerializer serializer = new XMLSerializer(out, outf);
115         try {
116             DOMSerializer domSerializer = serializer.asDOMSerializer();
117             domSerializer.serialize(doc);
118         } catch (Exception   e) {
119             if (CmsLog.getLog(this).isErrorEnabled()) {
120                 CmsLog.getLog(this).error("Xml parsing error", e);
121             }
122         }
123     }
124 
125     /**
126      * Calls a XML printer for converting a XML DOM document
127      * to a String.
128      * @param doc Document to be printed.
129      * @param out Writer to print to.
130      */
131     public void getXmlText(Document   doc, Writer   out) {
132         getXmlText(doc, out, getOriginalEncoding(doc));
133     }
134     
135     /**
136      * Used to import a node from a foreign document.
137      * @param doc Destination document that should import the node.
138      * @param node Node to be imported.
139      * @return New node that belongs to the document <code>doc</code>
140      */
141     public Node   importNode(Document   doc, Node   node) {
142         return ((org.apache.xerces.dom.DocumentImpl)doc).importNode(node, true);
143     }
144     
145     /**
146      * Parses the given text with the Xerces parser.
147      * @param in Reader with the input text.
148      * @return Parsed text as DOM document.
149      * @throws Exception
150      */
151     public Document   parse(Reader   in) throws Exception   {
152         return parse(new InputSource  (in));
153     }
154     
155     public Document   parse(InputStream   in) throws Exception   {
156         return parse(new InputSource  (in));
157     }
158     
159     /**
160      * Common internal method to actually parse input.
161      */ 
162     protected Document   parse(InputSource   input) throws Exception   {
163         DOMParser parser = new DOMParser();
164         try {
165             parser.setFeature("http://apache.org/xml/features/dom/include-ignorable-whitespace", false);
166         }
167         catch(SAXException   e) {
168             if(CmsLog.getLog(this).isWarnEnabled()  && !c_xercesWarning) {
169                 CmsLog.getLog(this).warn("Cannot set parser feature for apache xerces XML parser, you should use Xerces 1.1.1 or newer");
170                 c_xercesWarning = true;
171             }
172         }
173         parser.parse(input);
174         return parser.getDocument();
175     }
176     
177     public void serialize(Document   doc, OutputStream   in) throws Exception   {
178     }
179 
180     /**
181      * Gets a description of the parser.
182      * @return Parser description.
183      */
184     public String   toString() {
185         return "Apache Xerces XML Parser";
186     }
187 
188     private static int m_xercesVersion = 0;
189     
190     public String   getOriginalEncoding(Document   doc) {
191         // this functionality has experimental status in Apache Xerces parser 1.4.x and 2.x
192         // as it implements DOM level 3 functionality not completly and W3C' DOM3 API
193         // is in working draft stage
194         if (doc instanceof org.apache.xerces.dom.CoreDocumentImpl) {
195             org.apache.xerces.dom.CoreDocumentImpl d = (org.apache.xerces.dom.CoreDocumentImpl)doc;
196             String   result = null;
197             
198             // Xerces 1 and 2 APIs are different, we need to accomondate...
199             if ((m_xercesVersion == 2) || (m_xercesVersion == 0)) {
200                 try {
201                     result = (String  )d.getClass().getMethod("getXmlEncoding", new Class  []{}).invoke(d, new Object  []{});
202                     m_xercesVersion = 2;
203                 } catch (Throwable   t) {
204                     CmsLog.getLog(this).debug("Xerces 2 not found - getXmlEncoding() did not work", t);
205                 }
206             }
207             if ((m_xercesVersion == 1) || (m_xercesVersion == 0)) {
208                 try {
209                     result = (String  )d.getClass().getMethod("getEncoding", new Class  []{}).invoke(d, new Object  []{});
210                     m_xercesVersion = 1;
211                 } catch (Throwable   t) {
212                     CmsLog.getLog(this).debug("Xerces 1 not found - getEncoding() did not work", t);
213                 }
214             }           
215             // String result = ((org.apache.xerces.dom.CoreDocumentImpl)doc).getEncoding();
216             if ((result != null) && !"".equals(result.trim())) {
217                 return result;
218             }            
219         }
220         // in other cases we just return default encoding
221         return OpenCms.getSystemInfo().getDefaultEncoding();
222     }
223 }
224
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