1 /*
2 * Copyright 2000-2005 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 // XMLFilterImpl.java - base SAX2 filter implementation.
27 // http://www.saxproject.org
28 // Written by David Megginson
29 // NO WARRANTY! This class is in the Public Domain.
30 // $Id: XMLFilterImpl.java,v 1.3 2004/11/03 22:53:09 jsuttor Exp $
31
32 package org.xml.sax.helpers;
33
34 import java.io.IOException;
35
36 import org.xml.sax.XMLReader;
37 import org.xml.sax.XMLFilter;
38 import org.xml.sax.InputSource;
39 import org.xml.sax.Locator;
40 import org.xml.sax.Attributes;
41 import org.xml.sax.EntityResolver;
42 import org.xml.sax.DTDHandler;
43 import org.xml.sax.ContentHandler;
44 import org.xml.sax.ErrorHandler;
45 import org.xml.sax.SAXException;
46 import org.xml.sax.SAXParseException;
47 import org.xml.sax.SAXNotSupportedException;
48 import org.xml.sax.SAXNotRecognizedException;
49
50
51 /**
52 * Base class for deriving an XML filter.
53 *
54 * <blockquote>
55 * <em>This module, both source code and documentation, is in the
56 * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
57 * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
58 * for further information.
59 * </blockquote>
60 *
61 * <p>This class is designed to sit between an {@link org.xml.sax.XMLReader
62 * XMLReader} and the client application's event handlers. By default, it
63 * does nothing but pass requests up to the reader and events
64 * on to the handlers unmodified, but subclasses can override
65 * specific methods to modify the event stream or the configuration
66 * requests as they pass through.</p>
67 *
68 * @since SAX 2.0
69 * @author David Megginson
70 * @see org.xml.sax.XMLFilter
71 * @see org.xml.sax.XMLReader
72 * @see org.xml.sax.EntityResolver
73 * @see org.xml.sax.DTDHandler
74 * @see org.xml.sax.ContentHandler
75 * @see org.xml.sax.ErrorHandler
76 */
77 public class XMLFilterImpl
78 implements XMLFilter, EntityResolver, DTDHandler, ContentHandler, ErrorHandler
79 {
80
81
82 ////////////////////////////////////////////////////////////////////
83 // Constructors.
84 ////////////////////////////////////////////////////////////////////
85
86
87 /**
88 * Construct an empty XML filter, with no parent.
89 *
90 * <p>This filter will have no parent: you must assign a parent
91 * before you start a parse or do any configuration with
92 * setFeature or setProperty, unless you use this as a pure event
93 * consumer rather than as an {@link XMLReader}.</p>
94 *
95 * @see org.xml.sax.XMLReader#setFeature
96 * @see org.xml.sax.XMLReader#setProperty
97 * @see #setParent
98 */
99 public XMLFilterImpl ()
100 {
101 super();
102 }
103
104
105 /**
106 * Construct an XML filter with the specified parent.
107 *
108 * @see #setParent
109 * @see #getParent
110 */
111 public XMLFilterImpl (XMLReader parent)
112 {
113 super();
114 setParent(parent);
115 }
116
117
118
119 ////////////////////////////////////////////////////////////////////
120 // Implementation of org.xml.sax.XMLFilter.
121 ////////////////////////////////////////////////////////////////////
122
123
124 /**
125 * Set the parent reader.
126 *
127 * <p>This is the {@link org.xml.sax.XMLReader XMLReader} from which
128 * this filter will obtain its events and to which it will pass its
129 * configuration requests. The parent may itself be another filter.</p>
130 *
131 * <p>If there is no parent reader set, any attempt to parse
132 * or to set or get a feature or property will fail.</p>
133 *
134 * @param parent The parent XML reader.
135 * @see #getParent
136 */
137 public void setParent (XMLReader parent)
138 {
139 this.parent = parent;
140 }
141
142
143 /**
144 * Get the parent reader.
145 *
146 * @return The parent XML reader, or null if none is set.
147 * @see #setParent
148 */
149 public XMLReader getParent ()
150 {
151 return parent;
152 }
153
154
155
156 ////////////////////////////////////////////////////////////////////
157 // Implementation of org.xml.sax.XMLReader.
158 ////////////////////////////////////////////////////////////////////
159
160
161 /**
162 * Set the value of a feature.
163 *
164 * <p>This will always fail if the parent is null.</p>
165 *
166 * @param name The feature name.
167 * @param value The requested feature value.
168 * @exception org.xml.sax.SAXNotRecognizedException If the feature
169 * value can't be assigned or retrieved from the parent.
170 * @exception org.xml.sax.SAXNotSupportedException When the
171 * parent recognizes the feature name but
172 * cannot set the requested value.
173 */
174 public void setFeature (String name, boolean value)
175 throws SAXNotRecognizedException, SAXNotSupportedException
176 {
177 if (parent != null) {
178 parent.setFeature(name, value);
179 } else {
180 throw new SAXNotRecognizedException("Feature: " + name);
181 }
182 }
183
184
185 /**
186 * Look up the value of a feature.
187 *
188 * <p>This will always fail if the parent is null.</p>
189 *
190 * @param name The feature name.
191 * @return The current value of the feature.
192 * @exception org.xml.sax.SAXNotRecognizedException If the feature
193 * value can't be assigned or retrieved from the parent.
194 * @exception org.xml.sax.SAXNotSupportedException When the
195 * parent recognizes the feature name but
196 * cannot determine its value at this time.
197 */
198 public boolean getFeature (String name)
199 throws SAXNotRecognizedException, SAXNotSupportedException
200 {
201 if (parent != null) {
202 return parent.getFeature(name);
203 } else {
204 throw new SAXNotRecognizedException("Feature: " + name);
205 }
206 }
207
208
209 /**
210 * Set the value of a property.
211 *
212 * <p>This will always fail if the parent is null.</p>
213 *
214 * @param name The property name.
215 * @param value The requested property value.
216 * @exception org.xml.sax.SAXNotRecognizedException If the property
217 * value can't be assigned or retrieved from the parent.
218 * @exception org.xml.sax.SAXNotSupportedException When the
219 * parent recognizes the property name but
220 * cannot set the requested value.
221 */
222 public void setProperty (String name, Object value)
223 throws SAXNotRecognizedException, SAXNotSupportedException
224 {
225 if (parent != null) {
226 parent.setProperty(name, value);
227 } else {
228 throw new SAXNotRecognizedException("Property: " + name);
229 }
230 }
231
232
233 /**
234 * Look up the value of a property.
235 *
236 * @param name The property name.
237 * @return The current value of the property.
238 * @exception org.xml.sax.SAXNotRecognizedException If the property
239 * value can't be assigned or retrieved from the parent.
240 * @exception org.xml.sax.SAXNotSupportedException When the
241 * parent recognizes the property name but
242 * cannot determine its value at this time.
243 */
244 public Object getProperty (String name)
245 throws SAXNotRecognizedException, SAXNotSupportedException
246 {
247 if (parent != null) {
248 return parent.getProperty(name);
249 } else {
250 throw new SAXNotRecognizedException("Property: " + name);
251 }
252 }
253
254
255 /**
256 * Set the entity resolver.
257 *
258 * @param resolver The new entity resolver.
259 */
260 public void setEntityResolver (EntityResolver resolver)
261 {
262 entityResolver = resolver;
263 }
264
265
266 /**
267 * Get the current entity resolver.
268 *
269 * @return The current entity resolver, or null if none was set.
270 */
271 public EntityResolver getEntityResolver ()
272 {
273 return entityResolver;
274 }
275
276
277 /**
278 * Set the DTD event handler.
279 *
280 * @param handler the new DTD handler
281 */
282 public void setDTDHandler (DTDHandler handler)
283 {
284 dtdHandler = handler;
285 }
286
287
288 /**
289 * Get the current DTD event handler.
290 *
291 * @return The current DTD handler, or null if none was set.
292 */
293 public DTDHandler getDTDHandler ()
294 {
295 return dtdHandler;
296 }
297
298
299 /**
300 * Set the content event handler.
301 *
302 * @param handler the new content handler
303 */
304 public void setContentHandler (ContentHandler handler)
305 {
306 contentHandler = handler;
307 }
308
309
310 /**
311 * Get the content event handler.
312 *
313 * @return The current content handler, or null if none was set.
314 */
315 public ContentHandler getContentHandler ()
316 {
317 return contentHandler;
318 }
319
320
321 /**
322 * Set the error event handler.
323 *
324 * @param handler the new error handler
325 */
326 public void setErrorHandler (ErrorHandler handler)
327 {
328 errorHandler = handler;
329 }
330
331
332 /**
333 * Get the current error event handler.
334 *
335 * @return The current error handler, or null if none was set.
336 */
337 public ErrorHandler getErrorHandler ()
338 {
339 return errorHandler;
340 }
341
342
343 /**
344 * Parse a document.
345 *
346 * @param input The input source for the document entity.
347 * @exception org.xml.sax.SAXException Any SAX exception, possibly
348 * wrapping another exception.
349 * @exception java.io.IOException An IO exception from the parser,
350 * possibly from a byte stream or character stream
351 * supplied by the application.
352 */
353 public void parse (InputSource input)
354 throws SAXException, IOException
355 {
356 setupParse();
357 parent.parse(input);
358 }
359
360
361 /**
362 * Parse a document.
363 *
364 * @param systemId The system identifier as a fully-qualified URI.
365 * @exception org.xml.sax.SAXException Any SAX exception, possibly
366 * wrapping another exception.
367 * @exception java.io.IOException An IO exception from the parser,
368 * possibly from a byte stream or character stream
369 * supplied by the application.
370 */
371 public void parse (String systemId)
372 throws SAXException, IOException
373 {
374 parse(new InputSource(systemId));
375 }
376
377
378
379 ////////////////////////////////////////////////////////////////////
380 // Implementation of org.xml.sax.EntityResolver.
381 ////////////////////////////////////////////////////////////////////
382
383
384 /**
385 * Filter an external entity resolution.
386 *
387 * @param publicId The entity's public identifier, or null.
388 * @param systemId The entity's system identifier.
389 * @return A new InputSource or null for the default.
390 * @exception org.xml.sax.SAXException The client may throw
391 * an exception during processing.
392 * @exception java.io.IOException The client may throw an
393 * I/O-related exception while obtaining the
394 * new InputSource.
395 */
396 public InputSource resolveEntity (String publicId, String systemId)
397 throws SAXException, IOException
398 {
399 if (entityResolver != null) {
400 return entityResolver.resolveEntity(publicId, systemId);
401 } else {
402 return null;
403 }
404 }
405
406
407
408 ////////////////////////////////////////////////////////////////////
409 // Implementation of org.xml.sax.DTDHandler.
410 ////////////////////////////////////////////////////////////////////
411
412
413 /**
414 * Filter a notation declaration event.
415 *
416 * @param name The notation name.
417 * @param publicId The notation's public identifier, or null.
418 * @param systemId The notation's system identifier, or null.
419 * @exception org.xml.sax.SAXException The client may throw
420 * an exception during processing.
421 */
422 public void notationDecl (String name, String publicId, String systemId)
423 throws SAXException
424 {
425 if (dtdHandler != null) {
426 dtdHandler.notationDecl(name, publicId, systemId);
427 }
428 }
429
430
431 /**
432 * Filter an unparsed entity declaration event.
433 *
434 * @param name The entity name.
435 * @param publicId The entity's public identifier, or null.
436 * @param systemId The entity's system identifier, or null.
437 * @param notationName The name of the associated notation.
438 * @exception org.xml.sax.SAXException The client may throw
439 * an exception during processing.
440 */
441 public void unparsedEntityDecl (String name, String publicId,
442 String systemId, String notationName)
443 throws SAXException
444 {
445 if (dtdHandler != null) {
446 dtdHandler.unparsedEntityDecl(name, publicId, systemId,
447 notationName);
448 }
449 }
450
451
452
453 ////////////////////////////////////////////////////////////////////
454 // Implementation of org.xml.sax.ContentHandler.
455 ////////////////////////////////////////////////////////////////////
456
457
458 /**
459 * Filter a new document locator event.
460 *
461 * @param locator The document locator.
462 */
463 public void setDocumentLocator (Locator locator)
464 {
465 this.locator = locator;
466 if (contentHandler != null) {
467 contentHandler.setDocumentLocator(locator);
468 }
469 }
470
471
472 /**
473 * Filter a start document event.
474 *
475 * @exception org.xml.sax.SAXException The client may throw
476 * an exception during processing.
477 */
478 public void startDocument ()
479 throws SAXException
480 {
481 if (contentHandler != null) {
482 contentHandler.startDocument();
483 }
484 }
485
486
487 /**
488 * Filter an end document event.
489 *
490 * @exception org.xml.sax.SAXException The client may throw
491 * an exception during processing.
492 */
493 public void endDocument ()
494 throws SAXException
495 {
496 if (contentHandler != null) {
497 contentHandler.endDocument();
498 }
499 }
500
501
502 /**
503 * Filter a start Namespace prefix mapping event.
504 *
505 * @param prefix The Namespace prefix.
506 * @param uri The Namespace URI.
507 * @exception org.xml.sax.SAXException The client may throw
508 * an exception during processing.
509 */
510 public void startPrefixMapping (String prefix, String uri)
511 throws SAXException
512 {
513 if (contentHandler != null) {
514 contentHandler.startPrefixMapping(prefix, uri);
515 }
516 }
517
518
519 /**
520 * Filter an end Namespace prefix mapping event.
521 *
522 * @param prefix The Namespace prefix.
523 * @exception org.xml.sax.SAXException The client may throw
524 * an exception during processing.
525 */
526 public void endPrefixMapping (String prefix)
527 throws SAXException
528 {
529 if (contentHandler != null) {
530 contentHandler.endPrefixMapping(prefix);
531 }
532 }
533
534
535 /**
536 * Filter a start element event.
537 *
538 * @param uri The element's Namespace URI, or the empty string.
539 * @param localName The element's local name, or the empty string.
540 * @param qName The element's qualified (prefixed) name, or the empty
541 * string.
542 * @param atts The element's attributes.
543 * @exception org.xml.sax.SAXException The client may throw
544 * an exception during processing.
545 */
546 public void startElement (String uri, String localName, String qName,
547 Attributes atts)
548 throws SAXException
549 {
550 if (contentHandler != null) {
551 contentHandler.startElement(uri, localName, qName, atts);
552 }
553 }
554
555
556 /**
557 * Filter an end element event.
558 *
559 * @param uri The element's Namespace URI, or the empty string.
560 * @param localName The element's local name, or the empty string.
561 * @param qName The element's qualified (prefixed) name, or the empty
562 * string.
563 * @exception org.xml.sax.SAXException The client may throw
564 * an exception during processing.
565 */
566 public void endElement (String uri, String localName, String qName)
567 throws SAXException
568 {
569 if (contentHandler != null) {
570 contentHandler.endElement(uri, localName, qName);
571 }
572 }
573
574
575 /**
576 * Filter a character data event.
577 *
578 * @param ch An array of characters.
579 * @param start The starting position in the array.
580 * @param length The number of characters to use from the array.
581 * @exception org.xml.sax.SAXException The client may throw
582 * an exception during processing.
583 */
584 public void characters (char ch[], int start, int length)
585 throws SAXException
586 {
587 if (contentHandler != null) {
588 contentHandler.characters(ch, start, length);
589 }
590 }
591
592
593 /**
594 * Filter an ignorable whitespace event.
595 *
596 * @param ch An array of characters.
597 * @param start The starting position in the array.
598 * @param length The number of characters to use from the array.
599 * @exception org.xml.sax.SAXException The client may throw
600 * an exception during processing.
601 */
602 public void ignorableWhitespace (char ch[], int start, int length)
603 throws SAXException
604 {
605 if (contentHandler != null) {
606 contentHandler.ignorableWhitespace(ch, start, length);
607 }
608 }
609
610
611 /**
612 * Filter a processing instruction event.
613 *
614 * @param target The processing instruction target.
615 * @param data The text following the target.
616 * @exception org.xml.sax.SAXException The client may throw
617 * an exception during processing.
618 */
619 public void processingInstruction (String target, String data)
620 throws SAXException
621 {
622 if (contentHandler != null) {
623 contentHandler.processingInstruction(target, data);
624 }
625 }
626
627
628 /**
629 * Filter a skipped entity event.
630 *
631 * @param name The name of the skipped entity.
632 * @exception org.xml.sax.SAXException The client may throw
633 * an exception during processing.
634 */
635 public void skippedEntity (String name)
636 throws SAXException
637 {
638 if (contentHandler != null) {
639 contentHandler.skippedEntity(name);
640 }
641 }
642
643
644
645 ////////////////////////////////////////////////////////////////////
646 // Implementation of org.xml.sax.ErrorHandler.
647 ////////////////////////////////////////////////////////////////////
648
649
650 /**
651 * Filter a warning event.
652 *
653 * @param e The warning as an exception.
654 * @exception org.xml.sax.SAXException The client may throw
655 * an exception during processing.
656 */
657 public void warning (SAXParseException e)
658 throws SAXException
659 {
660 if (errorHandler != null) {
661 errorHandler.warning(e);
662 }
663 }
664
665
666 /**
667 * Filter an error event.
668 *
669 * @param e The error as an exception.
670 * @exception org.xml.sax.SAXException The client may throw
671 * an exception during processing.
672 */
673 public void error (SAXParseException e)
674 throws SAXException
675 {
676 if (errorHandler != null) {
677 errorHandler.error(e);
678 }
679 }
680
681
682 /**
683 * Filter a fatal error event.
684 *
685 * @param e The error as an exception.
686 * @exception org.xml.sax.SAXException The client may throw
687 * an exception during processing.
688 */
689 public void fatalError (SAXParseException e)
690 throws SAXException
691 {
692 if (errorHandler != null) {
693 errorHandler.fatalError(e);
694 }
695 }
696
697
698
699 ////////////////////////////////////////////////////////////////////
700 // Internal methods.
701 ////////////////////////////////////////////////////////////////////
702
703
704 /**
705 * Set up before a parse.
706 *
707 * <p>Before every parse, check whether the parent is
708 * non-null, and re-register the filter for all of the
709 * events.</p>
710 */
711 private void setupParse ()
712 {
713 if (parent == null) {
714 throw new NullPointerException("No parent for filter");
715 }
716 parent.setEntityResolver(this);
717 parent.setDTDHandler(this);
718 parent.setContentHandler(this);
719 parent.setErrorHandler(this);
720 }
721
722
723
724 ////////////////////////////////////////////////////////////////////
725 // Internal state.
726 ////////////////////////////////////////////////////////////////////
727
728 private XMLReader parent = null;
729 private Locator locator = null;
730 private EntityResolver entityResolver = null;
731 private DTDHandler dtdHandler = null;
732 private ContentHandler contentHandler = null;
733 private ErrorHandler errorHandler = null;
734
735 }
736
737 // end of XMLFilterImpl.java
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