1 /*
2 * Copyright (c) 2000, 2006, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 // DefaultHandler.java - default implementation of the core handlers.
27 // http://www.saxproject.org
28 // Written by David Megginson
29 // NO WARRANTY! This class is in the public domain.
30 // $Id: DefaultHandler.java,v 1.3 2006/04/13 02:06:32 jeffsuttor Exp $
31
32 package org.xml.sax.helpers;
33
34 import java.io.IOException;
35
36 import org.xml.sax.InputSource;
37 import org.xml.sax.Locator;
38 import org.xml.sax.Attributes;
39 import org.xml.sax.EntityResolver;
40 import org.xml.sax.DTDHandler;
41 import org.xml.sax.ContentHandler;
42 import org.xml.sax.ErrorHandler;
43 import org.xml.sax.SAXException;
44 import org.xml.sax.SAXParseException;
45
46
47 /**
48 * Default base class for SAX2 event handlers.
49 *
50 * <blockquote>
51 * <em>This module, both source code and documentation, is in the
52 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
53 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
54 * for further information.
55 * </blockquote>
56 *
57 * <p>This class is available as a convenience base class for SAX2
58 * applications: it provides default implementations for all of the
59 * callbacks in the four core SAX2 handler classes:</p>
60 *
61 * <ul>
62 * <li>{@link org.xml.sax.EntityResolver EntityResolver}</li>
63 * <li>{@link org.xml.sax.DTDHandler DTDHandler}</li>
64 * <li>{@link org.xml.sax.ContentHandler ContentHandler}</li>
65 * <li>{@link org.xml.sax.ErrorHandler ErrorHandler}</li>
66 * </ul>
67 *
68 * <p>Application writers can extend this class when they need to
69 * implement only part of an interface; parser writers can
70 * instantiate this class to provide default handlers when the
71 * application has not supplied its own.</p>
72 *
73 * <p>This class replaces the deprecated SAX1
74 * {@link org.xml.sax.HandlerBase HandlerBase} class.</p>
75 *
76 * @since 1.4, SAX 2.0
77 * @author David Megginson,
78 * @see org.xml.sax.EntityResolver
79 * @see org.xml.sax.DTDHandler
80 * @see org.xml.sax.ContentHandler
81 * @see org.xml.sax.ErrorHandler
82 */
83 public class DefaultHandler
84 implements EntityResolver, DTDHandler, ContentHandler, ErrorHandler
85 {
86
87
88 ////////////////////////////////////////////////////////////////////
89 // Default implementation of the EntityResolver interface.
90 ////////////////////////////////////////////////////////////////////
91
92 /**
93 * Resolve an external entity.
94 *
95 * <p>Always return null, so that the parser will use the system
96 * identifier provided in the XML document. This method implements
97 * the SAX default behaviour: application writers can override it
98 * in a subclass to do special translations such as catalog lookups
99 * or URI redirection.</p>
100 *
101 * @param publicId The public identifier, or null if none is
102 * available.
103 * @param systemId The system identifier provided in the XML
104 * document.
105 * @return The new input source, or null to require the
106 * default behaviour.
107 * @exception java.io.IOException If there is an error setting
108 * up the new input source.
109 * @exception org.xml.sax.SAXException Any SAX exception, possibly
110 * wrapping another exception.
111 * @see org.xml.sax.EntityResolver#resolveEntity
112 */
113 public InputSource resolveEntity (String publicId, String systemId)
114 throws IOException, SAXException
115 {
116 return null;
117 }
118
119
120
121 ////////////////////////////////////////////////////////////////////
122 // Default implementation of DTDHandler interface.
123 ////////////////////////////////////////////////////////////////////
124
125
126 /**
127 * Receive notification of a notation declaration.
128 *
129 * <p>By default, do nothing. Application writers may override this
130 * method in a subclass if they wish to keep track of the notations
131 * declared in a document.</p>
132 *
133 * @param name The notation name.
134 * @param publicId The notation public identifier, or null if not
135 * available.
136 * @param systemId The notation system identifier.
137 * @exception org.xml.sax.SAXException Any SAX exception, possibly
138 * wrapping another exception.
139 * @see org.xml.sax.DTDHandler#notationDecl
140 */
141 public void notationDecl (String name, String publicId, String systemId)
142 throws SAXException
143 {
144 // no op
145 }
146
147
148 /**
149 * Receive notification of an unparsed entity declaration.
150 *
151 * <p>By default, do nothing. Application writers may override this
152 * method in a subclass to keep track of the unparsed entities
153 * declared in a document.</p>
154 *
155 * @param name The entity name.
156 * @param publicId The entity public identifier, or null if not
157 * available.
158 * @param systemId The entity system identifier.
159 * @param notationName The name of the associated notation.
160 * @exception org.xml.sax.SAXException Any SAX exception, possibly
161 * wrapping another exception.
162 * @see org.xml.sax.DTDHandler#unparsedEntityDecl
163 */
164 public void unparsedEntityDecl (String name, String publicId,
165 String systemId, String notationName)
166 throws SAXException
167 {
168 // no op
169 }
170
171
172
173 ////////////////////////////////////////////////////////////////////
174 // Default implementation of ContentHandler interface.
175 ////////////////////////////////////////////////////////////////////
176
177
178 /**
179 * Receive a Locator object for document events.
180 *
181 * <p>By default, do nothing. Application writers may override this
182 * method in a subclass if they wish to store the locator for use
183 * with other document events.</p>
184 *
185 * @param locator A locator for all SAX document events.
186 * @see org.xml.sax.ContentHandler#setDocumentLocator
187 * @see org.xml.sax.Locator
188 */
189 public void setDocumentLocator (Locator locator)
190 {
191 // no op
192 }
193
194
195 /**
196 * Receive notification of the beginning of the document.
197 *
198 * <p>By default, do nothing. Application writers may override this
199 * method in a subclass to take specific actions at the beginning
200 * of a document (such as allocating the root node of a tree or
201 * creating an output file).</p>
202 *
203 * @exception org.xml.sax.SAXException Any SAX exception, possibly
204 * wrapping another exception.
205 * @see org.xml.sax.ContentHandler#startDocument
206 */
207 public void startDocument ()
208 throws SAXException
209 {
210 // no op
211 }
212
213
214 /**
215 * Receive notification of the end of the document.
216 *
217 * <p>By default, do nothing. Application writers may override this
218 * method in a subclass to take specific actions at the end
219 * of a document (such as finalising a tree or closing an output
220 * file).</p>
221 *
222 * @exception org.xml.sax.SAXException Any SAX exception, possibly
223 * wrapping another exception.
224 * @see org.xml.sax.ContentHandler#endDocument
225 */
226 public void endDocument ()
227 throws SAXException
228 {
229 // no op
230 }
231
232
233 /**
234 * Receive notification of the start of a Namespace mapping.
235 *
236 * <p>By default, do nothing. Application writers may override this
237 * method in a subclass to take specific actions at the start of
238 * each Namespace prefix scope (such as storing the prefix mapping).</p>
239 *
240 * @param prefix The Namespace prefix being declared.
241 * @param uri The Namespace URI mapped to the prefix.
242 * @exception org.xml.sax.SAXException Any SAX exception, possibly
243 * wrapping another exception.
244 * @see org.xml.sax.ContentHandler#startPrefixMapping
245 */
246 public void startPrefixMapping (String prefix, String uri)
247 throws SAXException
248 {
249 // no op
250 }
251
252
253 /**
254 * Receive notification of the end of a Namespace mapping.
255 *
256 * <p>By default, do nothing. Application writers may override this
257 * method in a subclass to take specific actions at the end of
258 * each prefix mapping.</p>
259 *
260 * @param prefix The Namespace prefix being declared.
261 * @exception org.xml.sax.SAXException Any SAX exception, possibly
262 * wrapping another exception.
263 * @see org.xml.sax.ContentHandler#endPrefixMapping
264 */
265 public void endPrefixMapping (String prefix)
266 throws SAXException
267 {
268 // no op
269 }
270
271
272 /**
273 * Receive notification of the start of an element.
274 *
275 * <p>By default, do nothing. Application writers may override this
276 * method in a subclass to take specific actions at the start of
277 * each element (such as allocating a new tree node or writing
278 * output to a file).</p>
279 *
280 * @param uri The Namespace URI, or the empty string if the
281 * element has no Namespace URI or if Namespace
282 * processing is not being performed.
283 * @param localName The local name (without prefix), or the
284 * empty string if Namespace processing is not being
285 * performed.
286 * @param qName The qualified name (with prefix), or the
287 * empty string if qualified names are not available.
288 * @param attributes The attributes attached to the element. If
289 * there are no attributes, it shall be an empty
290 * Attributes object.
291 * @exception org.xml.sax.SAXException Any SAX exception, possibly
292 * wrapping another exception.
293 * @see org.xml.sax.ContentHandler#startElement
294 */
295 public void startElement (String uri, String localName,
296 String qName, Attributes attributes)
297 throws SAXException
298 {
299 // no op
300 }
301
302
303 /**
304 * Receive notification of the end of an element.
305 *
306 * <p>By default, do nothing. Application writers may override this
307 * method in a subclass to take specific actions at the end of
308 * each element (such as finalising a tree node or writing
309 * output to a file).</p>
310 *
311 * @param uri The Namespace URI, or the empty string if the
312 * element has no Namespace URI or if Namespace
313 * processing is not being performed.
314 * @param localName The local name (without prefix), or the
315 * empty string if Namespace processing is not being
316 * performed.
317 * @param qName The qualified name (with prefix), or the
318 * empty string if qualified names are not available.
319 * @exception org.xml.sax.SAXException Any SAX exception, possibly
320 * wrapping another exception.
321 * @see org.xml.sax.ContentHandler#endElement
322 */
323 public void endElement (String uri, String localName, String qName)
324 throws SAXException
325 {
326 // no op
327 }
328
329
330 /**
331 * Receive notification of character data inside an element.
332 *
333 * <p>By default, do nothing. Application writers may override this
334 * method to take specific actions for each chunk of character data
335 * (such as adding the data to a node or buffer, or printing it to
336 * a file).</p>
337 *
338 * @param ch The characters.
339 * @param start The start position in the character array.
340 * @param length The number of characters to use from the
341 * character array.
342 * @exception org.xml.sax.SAXException Any SAX exception, possibly
343 * wrapping another exception.
344 * @see org.xml.sax.ContentHandler#characters
345 */
346 public void characters (char ch[], int start, int length)
347 throws SAXException
348 {
349 // no op
350 }
351
352
353 /**
354 * Receive notification of ignorable whitespace in element content.
355 *
356 * <p>By default, do nothing. Application writers may override this
357 * method to take specific actions for each chunk of ignorable
358 * whitespace (such as adding data to a node or buffer, or printing
359 * it to a file).</p>
360 *
361 * @param ch The whitespace characters.
362 * @param start The start position in the character array.
363 * @param length The number of characters to use from the
364 * character array.
365 * @exception org.xml.sax.SAXException Any SAX exception, possibly
366 * wrapping another exception.
367 * @see org.xml.sax.ContentHandler#ignorableWhitespace
368 */
369 public void ignorableWhitespace (char ch[], int start, int length)
370 throws SAXException
371 {
372 // no op
373 }
374
375
376 /**
377 * Receive notification of a processing instruction.
378 *
379 * <p>By default, do nothing. Application writers may override this
380 * method in a subclass to take specific actions for each
381 * processing instruction, such as setting status variables or
382 * invoking other methods.</p>
383 *
384 * @param target The processing instruction target.
385 * @param data The processing instruction data, or null if
386 * none is supplied.
387 * @exception org.xml.sax.SAXException Any SAX exception, possibly
388 * wrapping another exception.
389 * @see org.xml.sax.ContentHandler#processingInstruction
390 */
391 public void processingInstruction (String target, String data)
392 throws SAXException
393 {
394 // no op
395 }
396
397
398 /**
399 * Receive notification of a skipped entity.
400 *
401 * <p>By default, do nothing. Application writers may override this
402 * method in a subclass to take specific actions for each
403 * processing instruction, such as setting status variables or
404 * invoking other methods.</p>
405 *
406 * @param name The name of the skipped entity.
407 * @exception org.xml.sax.SAXException Any SAX exception, possibly
408 * wrapping another exception.
409 * @see org.xml.sax.ContentHandler#processingInstruction
410 */
411 public void skippedEntity (String name)
412 throws SAXException
413 {
414 // no op
415 }
416
417
418
419 ////////////////////////////////////////////////////////////////////
420 // Default implementation of the ErrorHandler interface.
421 ////////////////////////////////////////////////////////////////////
422
423
424 /**
425 * Receive notification of a parser warning.
426 *
427 * <p>The default implementation does nothing. Application writers
428 * may override this method in a subclass to take specific actions
429 * for each warning, such as inserting the message in a log file or
430 * printing it to the console.</p>
431 *
432 * @param e The warning information encoded as an exception.
433 * @exception org.xml.sax.SAXException Any SAX exception, possibly
434 * wrapping another exception.
435 * @see org.xml.sax.ErrorHandler#warning
436 * @see org.xml.sax.SAXParseException
437 */
438 public void warning (SAXParseException e)
439 throws SAXException
440 {
441 // no op
442 }
443
444
445 /**
446 * Receive notification of a recoverable parser error.
447 *
448 * <p>The default implementation does nothing. Application writers
449 * may override this method in a subclass to take specific actions
450 * for each error, such as inserting the message in a log file or
451 * printing it to the console.</p>
452 *
453 * @param e The error information encoded as an exception.
454 * @exception org.xml.sax.SAXException Any SAX exception, possibly
455 * wrapping another exception.
456 * @see org.xml.sax.ErrorHandler#warning
457 * @see org.xml.sax.SAXParseException
458 */
459 public void error (SAXParseException e)
460 throws SAXException
461 {
462 // no op
463 }
464
465
466 /**
467 * Report a fatal XML parsing error.
468 *
469 * <p>The default implementation throws a SAXParseException.
470 * Application writers may override this method in a subclass if
471 * they need to take specific actions for each fatal error (such as
472 * collecting all of the errors into a single report): in any case,
473 * the application must stop all regular processing when this
474 * method is invoked, since the document is no longer reliable, and
475 * the parser may no longer report parsing events.</p>
476 *
477 * @param e The error information encoded as an exception.
478 * @exception org.xml.sax.SAXException Any SAX exception, possibly
479 * wrapping another exception.
480 * @see org.xml.sax.ErrorHandler#fatalError
481 * @see org.xml.sax.SAXParseException
482 */
483 public void fatalError (SAXParseException e)
484 throws SAXException
485 {
486 throw e;
487 }
488
489 }
490
491 // end of DefaultHandler.java