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1 /*
2 * Copyright 1999-2005 The Apache Software Foundation.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package com.opensymphony.xwork2.util;
17
18 import java.util.Map;
19
20 import javax.xml.parsers.SAXParser;
21 import javax.xml.parsers.SAXParserFactory;
22 import javax.xml.transform.TransformerFactory;
23 import javax.xml.transform.dom.DOMResult;
24 import javax.xml.transform.sax.SAXTransformerFactory;
25 import javax.xml.transform.sax.TransformerHandler;
26
27 import org.w3c.dom.Document;
28 import org.w3c.dom.Element;
29 import org.w3c.dom.Node;
30 import org.xml.sax.Attributes;
31 import org.xml.sax.ContentHandler;
32 import org.xml.sax.InputSource;
33 import org.xml.sax.Locator;
34 import org.xml.sax.SAXException;
35 import org.xml.sax.SAXParseException;
36 import org.xml.sax.helpers.DefaultHandler;
37
38 import com.opensymphony.xwork2.ObjectFactory;
39 import com.opensymphony.xwork2.XWorkException;
40 import com.opensymphony.xwork2.util.location.Location;
41 import com.opensymphony.xwork2.util.location.LocationAttributes;
42 import com.opensymphony.xwork2.util.logging.Logger;
43 import com.opensymphony.xwork2.util.logging.LoggerFactory;
44
45 /**
46 * Helper class to create and retrieve information from location-enabled
47 * DOM-trees.
48 *
49 * @since 1.2
50 */
51 public class DomHelper {
52
53 private static final Logger LOG = LoggerFactory.getLogger(DomHelper.class);
54
55 public static final String XMLNS_URI = "http://www.w3.org/2000/xmlns/";
56
57 public static Location getLocationObject(Element element) {
58 return LocationAttributes.getLocation(element);
59 }
60
61
62 /**
63 * Creates a W3C Document that remembers the location of each element in
64 * the source file. The location of element nodes can then be retrieved
65 * using the {@link #getLocationObject(Element)} method.
66 *
67 * @param inputSource the inputSource to read the document from
68 */
69 public static Document parse(InputSource inputSource) {
70 return parse(inputSource, null);
71 }
72
73
74 /**
75 * Creates a W3C Document that remembers the location of each element in
76 * the source file. The location of element nodes can then be retrieved
77 * using the {@link #getLocationObject(Element)} method.
78 *
79 * @param inputSource the inputSource to read the document from
80 * @param dtdMappings a map of DTD names and public ids
81 */
82 public static Document parse(InputSource inputSource, Map dtdMappings) {
83
84 SAXParserFactory factory = null;
85 String parserProp = System.getProperty("xwork.saxParserFactory");
86 if (parserProp != null) {
87 try {
88 Class clazz = ObjectFactory.getObjectFactory().getClassInstance(parserProp);
89 factory = (SAXParserFactory) clazz.newInstance();
90 }
91 catch (ClassNotFoundException e) {
92 LOG.error("Unable to load saxParserFactory set by system property 'xwork.saxParserFactory': " + parserProp, e);
93 }
94 catch (Exception e) {
95 LOG.error("Unable to load saxParserFactory set by system property 'xwork.saxParserFactory': " + parserProp, e);
96 }
97 }
98
99 if (factory == null) {
100 factory = SAXParserFactory.newInstance();
101 }
102
103 factory.setValidating((dtdMappings != null));
104 factory.setNamespaceAware(true);
105
106 SAXParser parser = null;
107 try {
108 parser = factory.newSAXParser();
109 } catch (Exception ex) {
110 throw new XWorkException("Unable to create SAX parser", ex);
111 }
112
113
114 DOMBuilder builder = new DOMBuilder();
115
116 // Enhance the sax stream with location information
117 ContentHandler locationHandler = new LocationAttributes.Pipe(builder);
118
119 try {
120 parser.parse(inputSource, new StartHandler(locationHandler, dtdMappings));
121 } catch (Exception ex) {
122 throw new XWorkException(ex);
123 }
124
125 return builder.getDocument();
126 }
127
128 /**
129 * The <code>DOMBuilder</code> is a utility class that will generate a W3C
130 * DOM Document from SAX events.
131 *
132 * @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
133 */
134 static public class DOMBuilder implements ContentHandler {
135
136 /** The default transformer factory shared by all instances */
137 protected static SAXTransformerFactory FACTORY;
138
139 /** The transformer factory */
140 protected SAXTransformerFactory factory;
141
142 /** The result */
143 protected DOMResult result;
144
145 /** The parentNode */
146 protected Node parentNode;
147
148 protected ContentHandler nextHandler;
149
150 static {
151 String parserProp = System.getProperty("xwork.saxTransformerFactory");
152 if (parserProp != null) {
153 try {
154 Class clazz = ObjectFactory.getObjectFactory().getClassInstance(parserProp);
155 FACTORY = (SAXTransformerFactory) clazz.newInstance();
156 }
157 catch (ClassNotFoundException e) {
158 LOG.error("Unable to load SAXTransformerFactory set by system property 'xwork.saxTransformerFactory': " + parserProp, e);
159 }
160 catch (Exception e) {
161 LOG.error("Unable to load SAXTransformerFactory set by system property 'xwork.saxTransformerFactory': " + parserProp, e);
162 }
163 }
164
165 if (FACTORY == null) {
166 FACTORY = (SAXTransformerFactory) TransformerFactory.newInstance();
167 }
168 }
169
170 /**
171 * Construct a new instance of this DOMBuilder.
172 */
173 public DOMBuilder() {
174 this((Node) null);
175 }
176
177 /**
178 * Construct a new instance of this DOMBuilder.
179 */
180 public DOMBuilder(SAXTransformerFactory factory) {
181 this(factory, null);
182 }
183
184 /**
185 * Constructs a new instance that appends nodes to the given parent node.
186 */
187 public DOMBuilder(Node parentNode) {
188 this(null, parentNode);
189 }
190
191 /**
192 * Construct a new instance of this DOMBuilder.
193 */
194 public DOMBuilder(SAXTransformerFactory factory, Node parentNode) {
195 this.factory = factory == null? FACTORY: factory;
196 this.parentNode = parentNode;
197 setup();
198 }
199
200 /**
201 * Setup this instance transformer and result objects.
202 */
203 private void setup() {
204 try {
205 TransformerHandler handler = this.factory.newTransformerHandler();
206 nextHandler = handler;
207 if (this.parentNode != null) {
208 this.result = new DOMResult(this.parentNode);
209 } else {
210 this.result = new DOMResult();
211 }
212 handler.setResult(this.result);
213 } catch (javax.xml.transform.TransformerException local) {
214 throw new XWorkException("Fatal-Error: Unable to get transformer handler", local);
215 }
216 }
217
218 /**
219 * Return the newly built Document.
220 */
221 public Document getDocument() {
222 if (this.result == null || this.result.getNode() == null) {
223 return null;
224 } else if (this.result.getNode().getNodeType() == Node.DOCUMENT_NODE) {
225 return (Document) this.result.getNode();
226 } else {
227 return this.result.getNode().getOwnerDocument();
228 }
229 }
230
231 public void setDocumentLocator(Locator locator) {
232 nextHandler.setDocumentLocator(locator);
233 }
234
235 public void startDocument() throws SAXException {
236 nextHandler.startDocument();
237 }
238
239 public void endDocument() throws SAXException {
240 nextHandler.endDocument();
241 }
242
243 public void startElement(String uri, String loc, String raw, Attributes attrs) throws SAXException {
244 nextHandler.startElement(uri, loc, raw, attrs);
245 }
246
247 public void endElement(String arg0, String arg1, String arg2) throws SAXException {
248 nextHandler.endElement(arg0, arg1, arg2);
249 }
250
251 public void startPrefixMapping(String arg0, String arg1) throws SAXException {
252 nextHandler.startPrefixMapping(arg0, arg1);
253 }
254
255 public void endPrefixMapping(String arg0) throws SAXException {
256 nextHandler.endPrefixMapping(arg0);
257 }
258
259 public void characters(char[] arg0, int arg1, int arg2) throws SAXException {
260 nextHandler.characters(arg0, arg1, arg2);
261 }
262
263 public void ignorableWhitespace(char[] arg0, int arg1, int arg2) throws SAXException {
264 nextHandler.ignorableWhitespace(arg0, arg1, arg2);
265 }
266
267 public void processingInstruction(String arg0, String arg1) throws SAXException {
268 nextHandler.processingInstruction(arg0, arg1);
269 }
270
271 public void skippedEntity(String arg0) throws SAXException {
272 nextHandler.skippedEntity(arg0);
273 }
274 }
275
276 public static class StartHandler extends DefaultHandler {
277
278 private ContentHandler nextHandler;
279 private Map dtdMappings;
280
281 /**
282 * Create a filter that is chained to another handler.
283 * @param next the next handler in the chain.
284 */
285 public StartHandler(ContentHandler next, Map dtdMappings) {
286 nextHandler = next;
287 this.dtdMappings = dtdMappings;
288 }
289
290 public void setDocumentLocator(Locator locator) {
291 nextHandler.setDocumentLocator(locator);
292 }
293
294 public void startDocument() throws SAXException {
295 nextHandler.startDocument();
296 }
297
298 public void endDocument() throws SAXException {
299 nextHandler.endDocument();
300 }
301
302 public void startElement(String uri, String loc, String raw, Attributes attrs) throws SAXException {
303 nextHandler.startElement(uri, loc, raw, attrs);
304 }
305
306 public void endElement(String arg0, String arg1, String arg2) throws SAXException {
307 nextHandler.endElement(arg0, arg1, arg2);
308 }
309
310 public void startPrefixMapping(String arg0, String arg1) throws SAXException {
311 nextHandler.startPrefixMapping(arg0, arg1);
312 }
313
314 public void endPrefixMapping(String arg0) throws SAXException {
315 nextHandler.endPrefixMapping(arg0);
316 }
317
318 public void characters(char[] arg0, int arg1, int arg2) throws SAXException {
319 nextHandler.characters(arg0, arg1, arg2);
320 }
321
322 public void ignorableWhitespace(char[] arg0, int arg1, int arg2) throws SAXException {
323 nextHandler.ignorableWhitespace(arg0, arg1, arg2);
324 }
325
326 public void processingInstruction(String arg0, String arg1) throws SAXException {
327 nextHandler.processingInstruction(arg0, arg1);
328 }
329
330 public void skippedEntity(String arg0) throws SAXException {
331 nextHandler.skippedEntity(arg0);
332 }
333
334 public InputSource resolveEntity(String publicId, String systemId) {
335 if (dtdMappings != null && dtdMappings.containsKey(publicId)) {
336 String val = dtdMappings.get(publicId).toString();
337 return new InputSource(ClassLoaderUtil.getResourceAsStream(val, DomHelper.class));
338 }
339 return null;
340 }
341
342 public void warning(SAXParseException exception) {
343 }
344
345 public void error(SAXParseException exception) throws SAXException {
346 LOG.error(exception.getMessage() + " at (" + exception.getPublicId() + ":" +
347 exception.getLineNumber() + ":" + exception.getColumnNumber() + ")", exception);
348 throw exception;
349 }
350
351 public void fatalError(SAXParseException exception) throws SAXException {
352 LOG.fatal(exception.getMessage() + " at (" + exception.getPublicId() + ":" +
353 exception.getLineNumber() + ":" + exception.getColumnNumber() + ")", exception);
354 throw exception;
355 }
356 }
357
358 }