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 // SAX default handler base class.
27 // http://www.saxproject.org
28 // No warranty; no copyright -- use this as you will.
29 // $Id: HandlerBase.java,v 1.2 2005/06/10 03:50:47 jeffsuttor Exp $
30
31 package org.xml.sax;
32
33 /**
34 * Default base class for handlers.
35 *
36 * <blockquote>
37 * <em>This module, both source code and documentation, is in the
38 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
39 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
40 * for further information.
41 * </blockquote>
42 *
43 * <p>This class implements the default behaviour for four SAX1
44 * interfaces: EntityResolver, DTDHandler, DocumentHandler,
45 * and ErrorHandler. It is now obsolete, but is included in SAX2 to
46 * support legacy SAX1 applications. SAX2 applications should use
47 * the {@link org.xml.sax.helpers.DefaultHandler DefaultHandler}
48 * class instead.</p>
49 *
50 * <p>Application writers can extend this class when they need to
51 * implement only part of an interface; parser writers can
52 * instantiate this class to provide default handlers when the
53 * application has not supplied its own.</p>
54 *
55 * <p>Note that the use of this class is optional.</p>
56 *
57 * @deprecated This class works with the deprecated
58 * {@link org.xml.sax.DocumentHandler DocumentHandler}
59 * interface. It has been replaced by the SAX2
60 * {@link org.xml.sax.helpers.DefaultHandler DefaultHandler}
61 * class.
62 * @since 1.4, SAX 1.0
63 * @author David Megginson
64 * @see org.xml.sax.EntityResolver
65 * @see org.xml.sax.DTDHandler
66 * @see org.xml.sax.DocumentHandler
67 * @see org.xml.sax.ErrorHandler
68 */
69 public class HandlerBase
70 implements EntityResolver, DTDHandler, DocumentHandler, ErrorHandler
71 {
72
73
74 ////////////////////////////////////////////////////////////////////
75 // Default implementation of the EntityResolver interface.
76 ////////////////////////////////////////////////////////////////////
77
78 /**
79 * Resolve an external entity.
80 *
81 * <p>Always return null, so that the parser will use the system
82 * identifier provided in the XML document. This method implements
83 * the SAX default behaviour: application writers can override it
84 * in a subclass to do special translations such as catalog lookups
85 * or URI redirection.</p>
86 *
87 * @param publicId The public identifer, or null if none is
88 * available.
89 * @param systemId The system identifier provided in the XML
90 * document.
91 * @return The new input source, or null to require the
92 * default behaviour.
93 * @exception org.xml.sax.SAXException Any SAX exception, possibly
94 * wrapping another exception.
95 * @see org.xml.sax.EntityResolver#resolveEntity
96 */
97 public InputSource resolveEntity (String publicId, String systemId)
98 throws SAXException
99 {
100 return null;
101 }
102
103
104
105 ////////////////////////////////////////////////////////////////////
106 // Default implementation of DTDHandler interface.
107 ////////////////////////////////////////////////////////////////////
108
109
110 /**
111 * Receive notification of a notation declaration.
112 *
113 * <p>By default, do nothing. Application writers may override this
114 * method in a subclass if they wish to keep track of the notations
115 * declared in a document.</p>
116 *
117 * @param name The notation name.
118 * @param publicId The notation public identifier, or null if not
119 * available.
120 * @param systemId The notation system identifier.
121 * @see org.xml.sax.DTDHandler#notationDecl
122 */
123 public void notationDecl (String name, String publicId, String systemId)
124 {
125 // no op
126 }
127
128
129 /**
130 * Receive notification of an unparsed entity declaration.
131 *
132 * <p>By default, do nothing. Application writers may override this
133 * method in a subclass to keep track of the unparsed entities
134 * declared in a document.</p>
135 *
136 * @param name The entity name.
137 * @param publicId The entity public identifier, or null if not
138 * available.
139 * @param systemId The entity system identifier.
140 * @param notationName The name of the associated notation.
141 * @see org.xml.sax.DTDHandler#unparsedEntityDecl
142 */
143 public void unparsedEntityDecl (String name, String publicId,
144 String systemId, String notationName)
145 {
146 // no op
147 }
148
149
150
151 ////////////////////////////////////////////////////////////////////
152 // Default implementation of DocumentHandler interface.
153 ////////////////////////////////////////////////////////////////////
154
155
156 /**
157 * Receive a Locator object for document events.
158 *
159 * <p>By default, do nothing. Application writers may override this
160 * method in a subclass if they wish to store the locator for use
161 * with other document events.</p>
162 *
163 * @param locator A locator for all SAX document events.
164 * @see org.xml.sax.DocumentHandler#setDocumentLocator
165 * @see org.xml.sax.Locator
166 */
167 public void setDocumentLocator (Locator locator)
168 {
169 // no op
170 }
171
172
173 /**
174 * Receive notification of the beginning of the document.
175 *
176 * <p>By default, do nothing. Application writers may override this
177 * method in a subclass to take specific actions at the beginning
178 * of a document (such as allocating the root node of a tree or
179 * creating an output file).</p>
180 *
181 * @exception org.xml.sax.SAXException Any SAX exception, possibly
182 * wrapping another exception.
183 * @see org.xml.sax.DocumentHandler#startDocument
184 */
185 public void startDocument ()
186 throws SAXException
187 {
188 // no op
189 }
190
191
192 /**
193 * Receive notification of the end of the document.
194 *
195 * <p>By default, do nothing. Application writers may override this
196 * method in a subclass to take specific actions at the end
197 * of a document (such as finalising a tree or closing an output
198 * file).</p>
199 *
200 * @exception org.xml.sax.SAXException Any SAX exception, possibly
201 * wrapping another exception.
202 * @see org.xml.sax.DocumentHandler#endDocument
203 */
204 public void endDocument ()
205 throws SAXException
206 {
207 // no op
208 }
209
210
211 /**
212 * Receive notification of the start of an element.
213 *
214 * <p>By default, do nothing. Application writers may override this
215 * method in a subclass to take specific actions at the start of
216 * each element (such as allocating a new tree node or writing
217 * output to a file).</p>
218 *
219 * @param name The element type name.
220 * @param attributes The specified or defaulted attributes.
221 * @exception org.xml.sax.SAXException Any SAX exception, possibly
222 * wrapping another exception.
223 * @see org.xml.sax.DocumentHandler#startElement
224 */
225 public void startElement (String name, AttributeList attributes)
226 throws SAXException
227 {
228 // no op
229 }
230
231
232 /**
233 * Receive notification of the end of an element.
234 *
235 * <p>By default, do nothing. Application writers may override this
236 * method in a subclass to take specific actions at the end of
237 * each element (such as finalising a tree node or writing
238 * output to a file).</p>
239 *
240 * @param name the element name
241 * @exception org.xml.sax.SAXException Any SAX exception, possibly
242 * wrapping another exception.
243 * @see org.xml.sax.DocumentHandler#endElement
244 */
245 public void endElement (String name)
246 throws SAXException
247 {
248 // no op
249 }
250
251
252 /**
253 * Receive notification of character data inside an element.
254 *
255 * <p>By default, do nothing. Application writers may override this
256 * method to take specific actions for each chunk of character data
257 * (such as adding the data to a node or buffer, or printing it to
258 * a file).</p>
259 *
260 * @param ch The characters.
261 * @param start The start position in the character array.
262 * @param length The number of characters to use from the
263 * character array.
264 * @exception org.xml.sax.SAXException Any SAX exception, possibly
265 * wrapping another exception.
266 * @see org.xml.sax.DocumentHandler#characters
267 */
268 public void characters (char ch[], int start, int length)
269 throws SAXException
270 {
271 // no op
272 }
273
274
275 /**
276 * Receive notification of ignorable whitespace in element content.
277 *
278 * <p>By default, do nothing. Application writers may override this
279 * method to take specific actions for each chunk of ignorable
280 * whitespace (such as adding data to a node or buffer, or printing
281 * it to a file).</p>
282 *
283 * @param ch The whitespace characters.
284 * @param start The start position in the character array.
285 * @param length The number of characters to use from the
286 * character array.
287 * @exception org.xml.sax.SAXException Any SAX exception, possibly
288 * wrapping another exception.
289 * @see org.xml.sax.DocumentHandler#ignorableWhitespace
290 */
291 public void ignorableWhitespace (char ch[], int start, int length)
292 throws SAXException
293 {
294 // no op
295 }
296
297
298 /**
299 * Receive notification of a processing instruction.
300 *
301 * <p>By default, do nothing. Application writers may override this
302 * method in a subclass to take specific actions for each
303 * processing instruction, such as setting status variables or
304 * invoking other methods.</p>
305 *
306 * @param target The processing instruction target.
307 * @param data The processing instruction data, or null if
308 * none is supplied.
309 * @exception org.xml.sax.SAXException Any SAX exception, possibly
310 * wrapping another exception.
311 * @see org.xml.sax.DocumentHandler#processingInstruction
312 */
313 public void processingInstruction (String target, String data)
314 throws SAXException
315 {
316 // no op
317 }
318
319
320
321 ////////////////////////////////////////////////////////////////////
322 // Default implementation of the ErrorHandler interface.
323 ////////////////////////////////////////////////////////////////////
324
325
326 /**
327 * Receive notification of a parser warning.
328 *
329 * <p>The default implementation does nothing. Application writers
330 * may override this method in a subclass to take specific actions
331 * for each warning, such as inserting the message in a log file or
332 * printing it to the console.</p>
333 *
334 * @param e The warning information encoded as an exception.
335 * @exception org.xml.sax.SAXException Any SAX exception, possibly
336 * wrapping another exception.
337 * @see org.xml.sax.ErrorHandler#warning
338 * @see org.xml.sax.SAXParseException
339 */
340 public void warning (SAXParseException e)
341 throws SAXException
342 {
343 // no op
344 }
345
346
347 /**
348 * Receive notification of a recoverable parser error.
349 *
350 * <p>The default implementation does nothing. Application writers
351 * may override this method in a subclass to take specific actions
352 * for each error, such as inserting the message in a log file or
353 * printing it to the console.</p>
354 *
355 * @param e The warning information encoded as an exception.
356 * @exception org.xml.sax.SAXException Any SAX exception, possibly
357 * wrapping another exception.
358 * @see org.xml.sax.ErrorHandler#warning
359 * @see org.xml.sax.SAXParseException
360 */
361 public void error (SAXParseException e)
362 throws SAXException
363 {
364 // no op
365 }
366
367
368 /**
369 * Report a fatal XML parsing error.
370 *
371 * <p>The default implementation throws a SAXParseException.
372 * Application writers may override this method in a subclass if
373 * they need to take specific actions for each fatal error (such as
374 * collecting all of the errors into a single report): in any case,
375 * the application must stop all regular processing when this
376 * method is invoked, since the document is no longer reliable, and
377 * the parser may no longer report parsing events.</p>
378 *
379 * @param e The error information encoded as an exception.
380 * @exception org.xml.sax.SAXException Any SAX exception, possibly
381 * wrapping another exception.
382 * @see org.xml.sax.ErrorHandler#fatalError
383 * @see org.xml.sax.SAXParseException
384 */
385 public void fatalError (SAXParseException e)
386 throws SAXException
387 {
388 throw e;
389 }
390
391 }
392
393 // end of HandlerBase.java