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1   /**
2    *
3    * Copyright 2005 The Apache Software Foundation
4    *
5    *  Licensed under the Apache License, Version 2.0 (the "License");
6    *  you may not use this file except in compliance with the License.
7    *  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  package org.apache.geronimo.kernel.config.xstream;
18  
19  import javax.xml.parsers.DocumentBuilderFactory;
20  import javax.xml.parsers.DocumentBuilder;
21  import javax.xml.parsers.ParserConfigurationException;
22  
23  import com.thoughtworks.xstream.converters.Converter;
24  import com.thoughtworks.xstream.converters.MarshallingContext;
25  import com.thoughtworks.xstream.converters.UnmarshallingContext;
26  import com.thoughtworks.xstream.converters.ConversionException;
27  import com.thoughtworks.xstream.io.HierarchicalStreamWriter;
28  import com.thoughtworks.xstream.io.HierarchicalStreamReader;
29  import com.thoughtworks.xstream.io.xml.DomReader;
30  import com.thoughtworks.xstream.io.xml.DomWriter;
31  import org.w3c.dom.Document;
32  import org.w3c.dom.Element;
33  import org.apache.geronimo.kernel.util.XmlUtil;
34  
35  /**
36   * @version $Rev: 428843 $ $Date: 2006-08-04 11:43:59 -0700 (Fri, 04 Aug 2006) $
37   */
38  public class DomConverter implements Converter {
39      public boolean canConvert(Class clazz) {
40          return Document.class.isAssignableFrom(clazz) || Element.class.isAssignableFrom(clazz);
41      }
42  
43      public void marshal(Object object, HierarchicalStreamWriter writer, MarshallingContext marshallingContext) {
44          DomReader reader;
45          if (object instanceof Document) {
46              Document doc = (Document) object;
47              reader = new DomReader(doc);
48          } else {
49              Element element = (Element) object;
50              reader = new DomReader(element);
51          }
52  
53          copy(reader, writer);
54      }
55  
56      public Object unmarshal(HierarchicalStreamReader reader, UnmarshallingContext unmarshallingContext) {
57          DocumentBuilderFactory documentBuilderFactory = XmlUtil.newDocumentBuilderFactory();
58          DocumentBuilder documentBuilder = null;
59          try {
60              documentBuilder = documentBuilderFactory.newDocumentBuilder();
61          } catch (ParserConfigurationException e) {
62              throw new ConversionException("Cannot instantiate " + Document.class.getName(), e);
63          }
64          Document document = documentBuilder.newDocument();
65          DomWriter writer = new DomWriter(document);
66  
67          copy(reader, writer);
68  
69          if (Document.class.isAssignableFrom(unmarshallingContext.getRequiredType())) {
70              return document;
71          } else {
72              return document.getDocumentElement();
73          }
74      }
75  
76      public static void copy(HierarchicalStreamReader reader, HierarchicalStreamWriter writer) {
77          writer.startNode(reader.getNodeName());
78  
79          // write the attributes
80          int attributeCount = reader.getAttributeCount();
81          for (int i = 0; i < attributeCount; i++) {
82              String attributeName = reader.getAttributeName(i);
83              String attributeValue = reader.getAttribute(i);
84              writer.addAttribute(attributeName, attributeValue);
85          }
86  
87          // write the child nodes recursively
88          while (reader.hasMoreChildren()) {
89              reader.moveDown();
90              copy(reader, writer);
91              reader.moveUp();
92          }
93  
94          // write the context if any
95          String value = reader.getValue();
96          if (value != null && value.trim().length() > 0) {
97              writer.setValue(value);
98          }
99  
100         writer.endNode();
101     }
102 }