gomp-20050608-branch/libjava/classpath/external/sax/org/xml/sax/helpers/XMLReaderAdapter.java

   1 // XMLReaderAdapter.java - adapt an SAX2 XMLReader to a SAX1 Parser
   2 // http://www.saxproject.org
   3 // Written by David Megginson
   4 // NO WARRANTY!  This class is in the public domain.
   5 // $Id: XMLReaderAdapter.java,v 1.1 2004/12/23 22:38:42 mark Exp $
   6
   7 package org.xml.sax.helpers;
   8
   9 import java.io.IOException;
  10 import java.util.Locale;
  11
  12 import org.xml.sax.Parser;      // deprecated
  13 import org.xml.sax.Locator;
  14 import org.xml.sax.InputSource;
  15 import org.xml.sax.AttributeList; // deprecated
  16 import org.xml.sax.EntityResolver;
  17 import org.xml.sax.DTDHandler;
  18 import org.xml.sax.DocumentHandler; // deprecated
  19 import org.xml.sax.ErrorHandler;
  20 import org.xml.sax.SAXException;
  21
  22 import org.xml.sax.XMLReader;
  23 import org.xml.sax.Attributes;
  24 import org.xml.sax.ContentHandler;
  25 import org.xml.sax.SAXNotSupportedException;
  26
  27
  28 /**
  29  * Adapt a SAX2 XMLReader as a SAX1 Parser.
  30  *
  31  * <blockquote>
  32  * <em>This module, both source code and documentation, is in the
  33  * Public Domain, and comes with <strong>NO WARRANTY</strong>.</em>
  34  * See <a href='http://www.saxproject.org'>http://www.saxproject.org</a>
  35  * for further information.
  36  * </blockquote>
  37  *
  38  * <p>This class wraps a SAX2 {@link org.xml.sax.XMLReader XMLReader}
  39  * and makes it act as a SAX1 {@link org.xml.sax.Parser Parser}.  The XMLReader
  40  * must support a true value for the
  41  * http://xml.org/sax/features/namespace-prefixes property or parsing will fail
  42  * with a {@link org.xml.sax.SAXException SAXException}; if the XMLReader
  43  * supports a false value for the http://xml.org/sax/features/namespaces
  44  * property, that will also be used to improve efficiency.</p>
  45  *
  46  * @since SAX 2.0
  47  * @author David Megginson
  48  * @version 2.0.1 (sax2r2)
  49  * @see org.xml.sax.Parser
  50  * @see org.xml.sax.XMLReader
  51  */
  52 public class XMLReaderAdapter implements Parser, ContentHandler
  53 {
  54
  55 \f
  56     ////////////////////////////////////////////////////////////////////
  57     // Constructor.
  58     ////////////////////////////////////////////////////////////////////
  59
  60
  61     /**
  62      * Create a new adapter.
  63      *
  64      * <p>Use the "org.xml.sax.driver" property to locate the SAX2
  65      * driver to embed.</p>
  66      *
  67      * @exception org.xml.sax.SAXException If the embedded driver
  68      *            cannot be instantiated or if the
  69      *            org.xml.sax.driver property is not specified.
  70      */
  71     public XMLReaderAdapter ()
  72       throws SAXException
  73     {
  74         setup(XMLReaderFactory.createXMLReader());
  75     }
  76
  77
  78     /**
  79      * Create a new adapter.
  80      *
  81      * <p>Create a new adapter, wrapped around a SAX2 XMLReader.
  82      * The adapter will make the XMLReader act like a SAX1
  83      * Parser.</p>
  84      *
  85      * @param xmlReader The SAX2 XMLReader to wrap.
  86      * @exception java.lang.NullPointerException If the argument is null.
  87      */
  88     public XMLReaderAdapter (XMLReader xmlReader)
  89     {
  90         setup(xmlReader);
  91     }
  92
  93
  94
  95     /**
  96      * Internal setup.
  97      *
  98      * @param xmlReader The embedded XMLReader.
  99      */
 100     private void setup (XMLReader xmlReader)
 101     {
 102         if (xmlReader == null) {
 103             throw new NullPointerException("XMLReader must not be null");
 104         }
 105         this.xmlReader = xmlReader;
 106         qAtts = new AttributesAdapter();
 107     }
 108
 109
 110
 111     ////////////////////////////////////////////////////////////////////
 112     // Implementation of org.xml.sax.Parser.
 113     ////////////////////////////////////////////////////////////////////
 114
 115
 116     /**
 117      * Set the locale for error reporting.
 118      *
 119      * <p>This is not supported in SAX2, and will always throw
 120      * an exception.</p>
 121      *
 122      * @param locale the locale for error reporting.
 123      * @see org.xml.sax.Parser#setLocale
 124      * @exception org.xml.sax.SAXException Thrown unless overridden.
 125      */
 126     public void setLocale (Locale locale)
 127         throws SAXException
 128     {
 129         throw new SAXNotSupportedException("setLocale not supported");
 130     }
 131
 132
 133     /**
 134      * Register the entity resolver.
 135      *
 136      * @param resolver The new resolver.
 137      * @see org.xml.sax.Parser#setEntityResolver
 138      */
 139     public void setEntityResolver (EntityResolver resolver)
 140     {
 141         xmlReader.setEntityResolver(resolver);
 142     }
 143
 144
 145     /**
 146      * Register the DTD event handler.
 147      *
 148      * @param handler The new DTD event handler.
 149      * @see org.xml.sax.Parser#setDTDHandler
 150      */
 151     public void setDTDHandler (DTDHandler handler)
 152     {
 153         xmlReader.setDTDHandler(handler);
 154     }
 155
 156
 157     /**
 158      * Register the SAX1 document event handler.
 159      *
 160      * <p>Note that the SAX1 document handler has no Namespace
 161      * support.</p>
 162      *
 163      * @param handler The new SAX1 document event handler.
 164      * @see org.xml.sax.Parser#setDocumentHandler
 165      */
 166     public void setDocumentHandler (DocumentHandler handler)
 167     {
 168         documentHandler = handler;
 169     }
 170
 171
 172     /**
 173      * Register the error event handler.
 174      *
 175      * @param handler The new error event handler.
 176      * @see org.xml.sax.Parser#setErrorHandler
 177      */
 178     public void setErrorHandler (ErrorHandler handler)
 179     {
 180         xmlReader.setErrorHandler(handler);
 181     }
 182
 183
 184     /**
 185      * Parse the document.
 186      *
 187      * <p>This method will throw an exception if the embedded
 188      * XMLReader does not support the
 189      * http://xml.org/sax/features/namespace-prefixes property.</p>
 190      *
 191      * @param systemId The absolute URL of the document.
 192      * @exception java.io.IOException If there is a problem reading
 193      *            the raw content of the document.
 194      * @exception org.xml.sax.SAXException If there is a problem
 195      *            processing the document.
 196      * @see #parse(org.xml.sax.InputSource)
 197      * @see org.xml.sax.Parser#parse(java.lang.String)
 198      */
 199     public void parse (String systemId)
 200         throws IOException, SAXException
 201     {
 202         parse(new InputSource(systemId));
 203     }
 204
 205
 206     /**
 207      * Parse the document.
 208      *
 209      * <p>This method will throw an exception if the embedded
 210      * XMLReader does not support the
 211      * http://xml.org/sax/features/namespace-prefixes property.</p>
 212      *
 213      * @param input An input source for the document.
 214      * @exception java.io.IOException If there is a problem reading
 215      *            the raw content of the document.
 216      * @exception org.xml.sax.SAXException If there is a problem
 217      *            processing the document.
 218      * @see #parse(java.lang.String)
 219      * @see org.xml.sax.Parser#parse(org.xml.sax.InputSource)
 220      */
 221     public void parse (InputSource input)
 222         throws IOException, SAXException
 223     {
 224         setupXMLReader();
 225         xmlReader.parse(input);
 226     }
 227
 228
 229     /**
 230      * Set up the XML reader.
 231      */
 232     private void setupXMLReader ()
 233         throws SAXException
 234     {
 235         xmlReader.setFeature("http://xml.org/sax/features/namespace-prefixes", true);
 236         try {
 237             xmlReader.setFeature("http://xml.org/sax/features/namespaces",
 238                                  false);
 239         } catch (SAXException e) {
 240             // NO OP: it's just extra information, and we can ignore it
 241         }
 242         xmlReader.setContentHandler(this);
 243     }
 244
 245
 246 \f
 247     ////////////////////////////////////////////////////////////////////
 248     // Implementation of org.xml.sax.ContentHandler.
 249     ////////////////////////////////////////////////////////////////////
 250
 251
 252     /**
 253      * Set a document locator.
 254      *
 255      * @param locator The document locator.
 256      * @see org.xml.sax.ContentHandler#setDocumentLocator
 257      */
 258     public void setDocumentLocator (Locator locator)
 259     {
 260         if (documentHandler != null)
 261             documentHandler.setDocumentLocator(locator);
 262     }
 263
 264
 265     /**
 266      * Start document event.
 267      *
 268      * @exception org.xml.sax.SAXException The client may raise a
 269      *            processing exception.
 270      * @see org.xml.sax.ContentHandler#startDocument
 271      */
 272     public void startDocument ()
 273         throws SAXException
 274     {
 275         if (documentHandler != null)
 276             documentHandler.startDocument();
 277     }
 278
 279
 280     /**
 281      * End document event.
 282      *
 283      * @exception org.xml.sax.SAXException The client may raise a
 284      *            processing exception.
 285      * @see org.xml.sax.ContentHandler#endDocument
 286      */
 287     public void endDocument ()
 288         throws SAXException
 289     {
 290         if (documentHandler != null)
 291             documentHandler.endDocument();
 292     }
 293
 294
 295     /**
 296      * Adapt a SAX2 start prefix mapping event.
 297      *
 298      * @param prefix The prefix being mapped.
 299      * @param uri The Namespace URI being mapped to.
 300      * @see org.xml.sax.ContentHandler#startPrefixMapping
 301      */
 302     public void startPrefixMapping (String prefix, String uri)
 303     {
 304     }
 305
 306
 307     /**
 308      * Adapt a SAX2 end prefix mapping event.
 309      *
 310      * @param prefix The prefix being mapped.
 311      * @see org.xml.sax.ContentHandler#endPrefixMapping
 312      */
 313     public void endPrefixMapping (String prefix)
 314     {
 315     }
 316
 317
 318     /**
 319      * Adapt a SAX2 start element event.
 320      *
 321      * @param uri The Namespace URI.
 322      * @param localName The Namespace local name.
 323      * @param qName The qualified (prefixed) name.
 324      * @param atts The SAX2 attributes.
 325      * @exception org.xml.sax.SAXException The client may raise a
 326      *            processing exception.
 327      * @see org.xml.sax.ContentHandler#endDocument
 328      */
 329     public void startElement (String uri, String localName,
 330                               String qName, Attributes atts)
 331         throws SAXException
 332     {
 333         if (documentHandler != null) {
 334             qAtts.setAttributes(atts);
 335             documentHandler.startElement(qName, qAtts);
 336         }
 337     }
 338
 339
 340     /**
 341      * Adapt a SAX2 end element event.
 342      *
 343      * @param uri The Namespace URI.
 344      * @param localName The Namespace local name.
 345      * @param qName The qualified (prefixed) name.
 346      * @exception org.xml.sax.SAXException The client may raise a
 347      *            processing exception.
 348      * @see org.xml.sax.ContentHandler#endElement
 349      */
 350     public void endElement (String uri, String localName,
 351                             String qName)
 352         throws SAXException
 353     {
 354         if (documentHandler != null)
 355             documentHandler.endElement(qName);
 356     }
 357
 358
 359     /**
 360      * Adapt a SAX2 characters event.
 361      *
 362      * @param ch An array of characters.
 363      * @param start The starting position in the array.
 364      * @param length The number of characters to use.
 365      * @exception org.xml.sax.SAXException The client may raise a
 366      *            processing exception.
 367      * @see org.xml.sax.ContentHandler#characters
 368      */
 369     public void characters (char ch[], int start, int length)
 370         throws SAXException
 371     {
 372         if (documentHandler != null)
 373             documentHandler.characters(ch, start, length);
 374     }
 375
 376
 377     /**
 378      * Adapt a SAX2 ignorable whitespace event.
 379      *
 380      * @param ch An array of characters.
 381      * @param start The starting position in the array.
 382      * @param length The number of characters to use.
 383      * @exception org.xml.sax.SAXException The client may raise a
 384      *            processing exception.
 385      * @see org.xml.sax.ContentHandler#ignorableWhitespace
 386      */
 387     public void ignorableWhitespace (char ch[], int start, int length)
 388         throws SAXException
 389     {
 390         if (documentHandler != null)
 391             documentHandler.ignorableWhitespace(ch, start, length);
 392     }
 393
 394
 395     /**
 396      * Adapt a SAX2 processing instruction event.
 397      *
 398      * @param target The processing instruction target.
 399      * @param data The remainder of the processing instruction
 400      * @exception org.xml.sax.SAXException The client may raise a
 401      *            processing exception.
 402      * @see org.xml.sax.ContentHandler#processingInstruction
 403      */
 404     public void processingInstruction (String target, String data)
 405         throws SAXException
 406     {
 407         if (documentHandler != null)
 408             documentHandler.processingInstruction(target, data);
 409     }
 410
 411
 412     /**
 413      * Adapt a SAX2 skipped entity event.
 414      *
 415      * @param name The name of the skipped entity.
 416      * @see org.xml.sax.ContentHandler#skippedEntity
 417      * @exception org.xml.sax.SAXException Throwable by subclasses.
 418      */
 419     public void skippedEntity (String name)
 420         throws SAXException
 421     {
 422     }
 423
 424
 425 \f
 426     ////////////////////////////////////////////////////////////////////
 427     // Internal state.
 428     ////////////////////////////////////////////////////////////////////
 429
 430     XMLReader xmlReader;
 431     DocumentHandler documentHandler;
 432     AttributesAdapter qAtts;
 433
 434
 435 \f
 436     ////////////////////////////////////////////////////////////////////
 437     // Internal class.
 438     ////////////////////////////////////////////////////////////////////
 439
 440
 441     /**
 442      * Internal class to wrap a SAX2 Attributes object for SAX1.
 443      */
 444     final class AttributesAdapter implements AttributeList
 445     {
 446         AttributesAdapter ()
 447         {
 448         }
 449
 450
 451         /**
 452          * Set the embedded Attributes object.
 453          *
 454          * @param The embedded SAX2 Attributes.
 455          */
 456         void setAttributes (Attributes attributes)
 457         {
 458             this.attributes = attributes;
 459         }
 460
 461
 462         /**
 463          * Return the number of attributes.
 464          *
 465          * @return The length of the attribute list.
 466          * @see org.xml.sax.AttributeList#getLength
 467          */
 468         public int getLength ()
 469         {
 470             return attributes.getLength();
 471         }
 472
 473
 474         /**
 475          * Return the qualified (prefixed) name of an attribute by position.
 476          *
 477          * @return The qualified name.
 478          * @see org.xml.sax.AttributeList#getName
 479          */
 480         public String getName (int i)
 481         {
 482             return attributes.getQName(i);
 483         }
 484
 485
 486         /**
 487          * Return the type of an attribute by position.
 488          *
 489          * @return The type.
 490          * @see org.xml.sax.AttributeList#getType(int)
 491          */
 492         public String getType (int i)
 493         {
 494             return attributes.getType(i);
 495         }
 496
 497
 498         /**
 499          * Return the value of an attribute by position.
 500          *
 501          * @return The value.
 502          * @see org.xml.sax.AttributeList#getValue(int)
 503          */
 504         public String getValue (int i)
 505         {
 506             return attributes.getValue(i);
 507         }
 508
 509
 510         /**
 511          * Return the type of an attribute by qualified (prefixed) name.
 512          *
 513          * @return The type.
 514          * @see org.xml.sax.AttributeList#getType(java.lang.String)
 515          */
 516         public String getType (String qName)
 517         {
 518             return attributes.getType(qName);
 519         }
 520
 521
 522         /**
 523          * Return the value of an attribute by qualified (prefixed) name.
 524          *
 525          * @return The value.
 526          * @see org.xml.sax.AttributeList#getValue(java.lang.String)
 527          */
 528         public String getValue (String qName)
 529         {
 530             return attributes.getValue(qName);
 531         }
 532
 533         private Attributes attributes;
 534     }
 535
 536 }
 537
 538 // end of XMLReaderAdapter.java