1 /*
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   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
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   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  *
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  23  * questions.
  24  */
  25 
  26 package javax.xml.parsers;
  27 
  28 import javax.xml.validation.Schema;
  29 
  30 /**
  31  * Defines a factory API that enables applications to obtain a
  32  * parser that produces DOM object trees from XML documents.
  33  *
  34  * @author <a href="mailto:Jeff.Suttor@Sun.com">Jeff Suttor</a>
  35  * @author <a href="mailto:Neeraj.Bajaj@sun.com">Neeraj Bajaj</a>
  36  *
  37  * @version $Revision: 1.9 $, $Date: 2010/05/25 16:19:44 $
  38 
  39  */
  40 
  41 public abstract class DocumentBuilderFactory {
  42 
  43     private boolean validating = false;
  44     private boolean namespaceAware = false;
  45     private boolean whitespace = false;
  46     private boolean expandEntityRef = true;
  47     private boolean ignoreComments = false;
  48     private boolean coalescing = false;
  49 
  50     /**
  51      * <p>Protected constructor to prevent instantiation.
  52      * Use {@link #newInstance()}.</p>
  53      */
  54     protected DocumentBuilderFactory () {
  55     }
  56 
  57     /**
  58      * Obtain a new instance of a
  59      * <code>DocumentBuilderFactory</code>. This static method creates
  60      * a new factory instance.
  61      * This method uses the following ordered lookup procedure to determine
  62      * the <code>DocumentBuilderFactory</code> implementation class to
  63      * load:
  64      * <ul>
  65      * <li>
  66      * Use the <code>javax.xml.parsers.DocumentBuilderFactory</code> system
  67      * property.
  68      * </li>
  69      * <li>
  70      * Use the properties file "lib/jaxp.properties" in the JRE directory.
  71      * This configuration file is in standard <code>java.util.Properties
  72      * </code> format and contains the fully qualified name of the
  73      * implementation class with the key being the system property defined
  74      * above.
  75      *
  76      * The jaxp.properties file is read only once by the JAXP implementation
  77      * and it's values are then cached for future use.  If the file does not exist
  78      * when the first attempt is made to read from it, no further attempts are
  79      * made to check for its existence.  It is not possible to change the value
  80      * of any property in jaxp.properties after it has been read for the first time.
  81      * </li>
  82      * <li>
  83      * Uses the service-provider loading facilities, defined by the 
  84      * {@link java.util.ServiceLoader} class, to attempt to locate and load an
  85      * implementation of the service.
  86      * </li>
  87      * <li>
  88      * Otherwise, the system-default implementation is returned.
  89      * </li>
  90      * </ul>
  91      *
  92      * Once an application has obtained a reference to a
  93      * <code>DocumentBuilderFactory</code> it can use the factory to
  94      * configure and obtain parser instances.
  95      *
  96      *
  97      * <h2>Tip for Trouble-shooting</h2>
  98      * <p>Setting the <code>jaxp.debug</code> system property will cause
  99      * this method to print a lot of debug messages
 100      * to <code>System.err</code> about what it is doing and where it is looking at.</p>
 101      *
 102      * <p> If you have problems loading {@link DocumentBuilder}s, try:</p>
 103      * <pre>
 104      * java -Djaxp.debug=1 YourProgram ....
 105      * </pre>
 106      *
 107      * @return New instance of a <code>DocumentBuilderFactory</code>
 108      *
 109      * @throws FactoryConfigurationError in case of {@linkplain
 110      * java.util.ServiceConfigurationError service configuration error} or if
 111      * the implementation is not available or cannot be instantiated.
 112      */
 113     public static DocumentBuilderFactory newInstance() {
 114         return FactoryFinder.find(
 115                 /* The default property name according to the JAXP spec */
 116                 DocumentBuilderFactory.class, // "javax.xml.parsers.DocumentBuilderFactory"
 117                 /* The fallback implementation class name */
 118                 "com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl");
 119     }
 120 
 121     /**
 122      * <p>Obtain a new instance of a <code>DocumentBuilderFactory</code> from class name.
 123      * This function is useful when there are multiple providers in the classpath.
 124      * It gives more control to the application as it can specify which provider
 125      * should be loaded.</p>
 126      *
 127      * <p>Once an application has obtained a reference to a <code>DocumentBuilderFactory</code>
 128      * it can use the factory to configure and obtain parser instances.</p>
 129      *
 130      *
 131      * <h2>Tip for Trouble-shooting</h2>
 132      * <p>Setting the <code>jaxp.debug</code> system property will cause
 133      * this method to print a lot of debug messages
 134      * to <code>System.err</code> about what it is doing and where it is looking at.</p>
 135      *
 136      * <p> If you have problems try:</p>
 137      * <pre>
 138      * java -Djaxp.debug=1 YourProgram ....
 139      * </pre>
 140      *
 141      * @param factoryClassName fully qualified factory class name that provides implementation of <code>javax.xml.parsers.DocumentBuilderFactory</code>.
 142      *
 143      * @param classLoader <code>ClassLoader</code> used to load the factory class. If <code>null</code>
 144      *                     current <code>Thread</code>'s context classLoader is used to load the factory class.
 145      *
 146      * @return New instance of a <code>DocumentBuilderFactory</code>
 147      *
 148      * @throws FactoryConfigurationError if <code>factoryClassName</code> is <code>null</code>, or
 149      *                                   the factory class cannot be loaded, instantiated.
 150      *
 151      * @see #newInstance()
 152      *
 153      * @since 1.6
 154      */
 155     public static DocumentBuilderFactory newInstance(String factoryClassName, ClassLoader classLoader){
 156             //do not fallback if given classloader can't find the class, throw exception
 157             return FactoryFinder.newInstance(DocumentBuilderFactory.class,
 158                         factoryClassName, classLoader, false);
 159     }
 160 
 161     /**
 162      * Creates a new instance of a {@link javax.xml.parsers.DocumentBuilder}
 163      * using the currently configured parameters.
 164      *
 165      * @return A new instance of a DocumentBuilder.
 166      *
 167      * @throws ParserConfigurationException if a DocumentBuilder
 168      *   cannot be created which satisfies the configuration requested.
 169      */
 170 
 171     public abstract DocumentBuilder newDocumentBuilder()
 172         throws ParserConfigurationException;
 173 
 174 
 175     /**
 176      * Specifies that the parser produced by this code will
 177      * provide support for XML namespaces. By default the value of this is set
 178      * to <code>false</code>
 179      *
 180      * @param awareness true if the parser produced will provide support
 181      *                  for XML namespaces; false otherwise.
 182      */
 183 
 184     public void setNamespaceAware(boolean awareness) {
 185         this.namespaceAware = awareness;
 186     }
 187 
 188     /**
 189      * Specifies that the parser produced by this code will
 190      * validate documents as they are parsed. By default the value of this
 191      * is set to <code>false</code>.
 192      *
 193      * <p>
 194      * Note that "the validation" here means
 195      * <a href="http://www.w3.org/TR/REC-xml#proc-types">a validating
 196      * parser</a> as defined in the XML recommendation.
 197      * In other words, it essentially just controls the DTD validation.
 198      * (except the legacy two properties defined in JAXP 1.2.)
 199      * </p>
 200      *
 201      * <p>
 202      * To use modern schema languages such as W3C XML Schema or
 203      * RELAX NG instead of DTD, you can configure your parser to be
 204      * a non-validating parser by leaving the {@link #setValidating(boolean)}
 205      * method <code>false</code>, then use the {@link #setSchema(Schema)}
 206      * method to associate a schema to a parser.
 207      * </p>
 208      *
 209      * @param validating true if the parser produced will validate documents
 210      *                   as they are parsed; false otherwise.
 211      */
 212 
 213     public void setValidating(boolean validating) {
 214         this.validating = validating;
 215     }
 216 
 217     /**
 218      * Specifies that the parsers created by this  factory must eliminate
 219      * whitespace in element content (sometimes known loosely as
 220      * 'ignorable whitespace') when parsing XML documents (see XML Rec
 221      * 2.10). Note that only whitespace which is directly contained within
 222      * element content that has an element only content model (see XML
 223      * Rec 3.2.1) will be eliminated. Due to reliance on the content model
 224      * this setting requires the parser to be in validating mode. By default
 225      * the value of this is set to <code>false</code>.
 226      *
 227      * @param whitespace true if the parser created must eliminate whitespace
 228      *                   in the element content when parsing XML documents;
 229      *                   false otherwise.
 230      */
 231 
 232     public void setIgnoringElementContentWhitespace(boolean whitespace) {
 233         this.whitespace = whitespace;
 234     }
 235 
 236     /**
 237      * Specifies that the parser produced by this code will
 238      * expand entity reference nodes. By default the value of this is set to
 239      * <code>true</code>
 240      *
 241      * @param expandEntityRef true if the parser produced will expand entity
 242      *                        reference nodes; false otherwise.
 243      */
 244 
 245     public void setExpandEntityReferences(boolean expandEntityRef) {
 246         this.expandEntityRef = expandEntityRef;
 247     }
 248 
 249     /**
 250      * <p>Specifies that the parser produced by this code will
 251      * ignore comments. By default the value of this is set to <code>false
 252      * </code>.</p>
 253      *
 254      * @param ignoreComments <code>boolean</code> value to ignore comments during processing
 255      */
 256 
 257     public void setIgnoringComments(boolean ignoreComments) {
 258         this.ignoreComments = ignoreComments;
 259     }
 260 
 261     /**
 262      * Specifies that the parser produced by this code will
 263      * convert CDATA nodes to Text nodes and append it to the
 264      * adjacent (if any) text node. By default the value of this is set to
 265      * <code>false</code>
 266      *
 267      * @param coalescing  true if the parser produced will convert CDATA nodes
 268      *                    to Text nodes and append it to the adjacent (if any)
 269      *                    text node; false otherwise.
 270      */
 271 
 272     public void setCoalescing(boolean coalescing) {
 273         this.coalescing = coalescing;
 274     }
 275 
 276     /**
 277      * Indicates whether or not the factory is configured to produce
 278      * parsers which are namespace aware.
 279      *
 280      * @return  true if the factory is configured to produce parsers which
 281      *          are namespace aware; false otherwise.
 282      */
 283 
 284     public boolean isNamespaceAware() {
 285         return namespaceAware;
 286     }
 287 
 288     /**
 289      * Indicates whether or not the factory is configured to produce
 290      * parsers which validate the XML content during parse.
 291      *
 292      * @return  true if the factory is configured to produce parsers
 293      *          which validate the XML content during parse; false otherwise.
 294      */
 295 
 296     public boolean isValidating() {
 297         return validating;
 298     }
 299 
 300     /**
 301      * Indicates whether or not the factory is configured to produce
 302      * parsers which ignore ignorable whitespace in element content.
 303      *
 304      * @return  true if the factory is configured to produce parsers
 305      *          which ignore ignorable whitespace in element content;
 306      *          false otherwise.
 307      */
 308 
 309     public boolean isIgnoringElementContentWhitespace() {
 310         return whitespace;
 311     }
 312 
 313     /**
 314      * Indicates whether or not the factory is configured to produce
 315      * parsers which expand entity reference nodes.
 316      *
 317      * @return  true if the factory is configured to produce parsers
 318      *          which expand entity reference nodes; false otherwise.
 319      */
 320 
 321     public boolean isExpandEntityReferences() {
 322         return expandEntityRef;
 323     }
 324 
 325     /**
 326      * Indicates whether or not the factory is configured to produce
 327      * parsers which ignores comments.
 328      *
 329      * @return  true if the factory is configured to produce parsers
 330      *          which ignores comments; false otherwise.
 331      */
 332 
 333     public boolean isIgnoringComments() {
 334         return ignoreComments;
 335     }
 336 
 337     /**
 338      * Indicates whether or not the factory is configured to produce
 339      * parsers which converts CDATA nodes to Text nodes and appends it to
 340      * the adjacent (if any) Text node.
 341      *
 342      * @return  true if the factory is configured to produce parsers
 343      *          which converts CDATA nodes to Text nodes and appends it to
 344      *          the adjacent (if any) Text node; false otherwise.
 345      */
 346 
 347     public boolean isCoalescing() {
 348         return coalescing;
 349     }
 350 
 351     /**
 352      * Allows the user to set specific attributes on the underlying
 353      * implementation.
 354      *
 355      * @param name The name of the attribute.
 356      * @param value The value of the attribute.
 357      *
 358      * @throws IllegalArgumentException thrown if the underlying
 359      *   implementation doesn't recognize the attribute.
 360      */
 361     public abstract void setAttribute(String name, Object value)
 362                 throws IllegalArgumentException;
 363 
 364     /**
 365      * Allows the user to retrieve specific attributes on the underlying
 366      * implementation.
 367      *
 368      * @param name The name of the attribute.
 369      *
 370      * @return value The value of the attribute.
 371      *
 372      * @throws IllegalArgumentException thrown if the underlying
 373      *   implementation doesn't recognize the attribute.
 374      */
 375     public abstract Object getAttribute(String name)
 376                 throws IllegalArgumentException;
 377 
 378     /**
 379      * <p>Set a feature for this <code>DocumentBuilderFactory</code> and <code>DocumentBuilder</code>s created by this factory.</p>
 380      *
 381      * <p>
 382      * Feature names are fully qualified {@link java.net.URI}s.
 383      * Implementations may define their own features.
 384      * A {@link ParserConfigurationException} is thrown if this <code>DocumentBuilderFactory</code> or the
 385      * <code>DocumentBuilder</code>s it creates cannot support the feature.
 386      * It is possible for a <code>DocumentBuilderFactory</code> to expose a feature value but be unable to change its state.
 387      * </p>
 388      *
 389      * <p>
 390      * All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature.
 391      * When the feature is:</p>
 392      * <ul>
 393      *   <li>
 394      *     <code>true</code>: the implementation will limit XML processing to conform to implementation limits.
 395      *     Examples include enity expansion limits and XML Schema constructs that would consume large amounts of resources.
 396      *     If XML processing is limited for security reasons, it will be reported via a call to the registered
 397      *    {@link org.xml.sax.ErrorHandler#fatalError(SAXParseException exception)}.
 398      *     See {@link  DocumentBuilder#setErrorHandler(org.xml.sax.ErrorHandler errorHandler)}.
 399      *   </li>
 400      *   <li>
 401      *     <code>false</code>: the implementation will processing XML according to the XML specifications without
 402      *     regard to possible implementation limits.
 403      *   </li>
 404      * </ul>
 405      *
 406      * @param name Feature name.
 407      * @param value Is feature state <code>true</code> or <code>false</code>.
 408      *
 409      * @throws ParserConfigurationException if this <code>DocumentBuilderFactory</code> or the <code>DocumentBuilder</code>s
 410      *   it creates cannot support this feature.
 411      * @throws NullPointerException If the <code>name</code> parameter is null.
 412      */
 413     public abstract void setFeature(String name, boolean value)
 414             throws ParserConfigurationException;
 415 
 416     /**
 417      * <p>Get the state of the named feature.</p>
 418      *
 419      * <p>
 420      * Feature names are fully qualified {@link java.net.URI}s.
 421      * Implementations may define their own features.
 422      * An {@link ParserConfigurationException} is thrown if this <code>DocumentBuilderFactory</code> or the
 423      * <code>DocumentBuilder</code>s it creates cannot support the feature.
 424      * It is possible for an <code>DocumentBuilderFactory</code> to expose a feature value but be unable to change its state.
 425      * </p>
 426      *
 427      * @param name Feature name.
 428      *
 429      * @return State of the named feature.
 430      *
 431      * @throws ParserConfigurationException if this <code>DocumentBuilderFactory</code>
 432      *   or the <code>DocumentBuilder</code>s it creates cannot support this feature.
 433      */
 434     public abstract boolean getFeature(String name)
 435             throws ParserConfigurationException;
 436 
 437 
 438     /**
 439      * Gets the {@link Schema} object specified through
 440      * the {@link #setSchema(Schema schema)} method.
 441      *
 442      * @return
 443      *      the {@link Schema} object that was last set through
 444      *      the {@link #setSchema(Schema)} method, or null
 445      *      if the method was not invoked since a {@link DocumentBuilderFactory}
 446      *      is created.
 447      *
 448      * @throws UnsupportedOperationException When implementation does not
 449      *   override this method.
 450      *
 451      * @since 1.5
 452      */
 453     public Schema getSchema() {
 454         throw new UnsupportedOperationException(
 455             "This parser does not support specification \""
 456             + this.getClass().getPackage().getSpecificationTitle()
 457             + "\" version \""
 458             + this.getClass().getPackage().getSpecificationVersion()
 459             + "\""
 460             );
 461 
 462     }
 463 
 464     /**
 465      * <p>Set the {@link Schema} to be used by parsers created
 466      * from this factory.
 467      *
 468      * <p>
 469      * When a {@link Schema} is non-null, a parser will use a validator
 470      * created from it to validate documents before it passes information
 471      * down to the application.
 472      *
 473      * <p>When errors are found by the validator, the parser is responsible
 474      * to report them to the user-specified {@link org.xml.sax.ErrorHandler}
 475      * (or if the error handler is not set, ignore them or throw them), just
 476      * like any other errors found by the parser itself.
 477      * In other words, if the user-specified {@link org.xml.sax.ErrorHandler}
 478      * is set, it must receive those errors, and if not, they must be
 479      * treated according to the implementation specific
 480      * default error handling rules.
 481      *
 482      * <p>
 483      * A validator may modify the outcome of a parse (for example by
 484      * adding default values that were missing in documents), and a parser
 485      * is responsible to make sure that the application will receive
 486      * modified DOM trees.
 487      *
 488      * <p>
 489      * Initialy, null is set as the {@link Schema}.
 490      *
 491      * <p>
 492      * This processing will take effect even if
 493      * the {@link #isValidating()} method returns <code>false</code>.
 494      *
 495      * <p>It is an error to use
 496      * the <code>http://java.sun.com/xml/jaxp/properties/schemaSource</code>
 497      * property and/or the <code>http://java.sun.com/xml/jaxp/properties/schemaLanguage</code>
 498      * property in conjunction with a {@link Schema} object.
 499      * Such configuration will cause a {@link ParserConfigurationException}
 500      * exception when the {@link #newDocumentBuilder()} is invoked.</p>
 501      *
 502      *
 503      * <h4>Note for implmentors</h4>
 504      *
 505      * <p>
 506      * A parser must be able to work with any {@link Schema}
 507      * implementation. However, parsers and schemas are allowed
 508      * to use implementation-specific custom mechanisms
 509      * as long as they yield the result described in the specification.
 510      * </p>
 511      *
 512      * @param schema <code>Schema</code> to use or <code>null</code>
 513      *   to remove a schema.
 514      *
 515      * @throws UnsupportedOperationException When implementation does not
 516      *   override this method.
 517      *
 518      * @since 1.5
 519      */
 520     public void setSchema(Schema schema) {
 521         throw new UnsupportedOperationException(
 522             "This parser does not support specification \""
 523             + this.getClass().getPackage().getSpecificationTitle()
 524             + "\" version \""
 525             + this.getClass().getPackage().getSpecificationVersion()
 526             + "\""
 527             );
 528     }
 529 
 530 
 531 
 532     /**
 533      * <p>Set state of XInclude processing.</p>
 534      *
 535      * <p>If XInclude markup is found in the document instance, should it be
 536      * processed as specified in <a href="http://www.w3.org/TR/xinclude/">
 537      * XML Inclusions (XInclude) Version 1.0</a>.</p>
 538      *
 539      * <p>XInclude processing defaults to <code>false</code>.</p>
 540      *
 541      * @param state Set XInclude processing to <code>true</code> or
 542      *   <code>false</code>
 543      *
 544      * @throws UnsupportedOperationException When implementation does not
 545      *   override this method.
 546      *
 547      * @since 1.5
 548      */
 549     public void setXIncludeAware(final boolean state) {
 550         if (state) {
 551             throw new UnsupportedOperationException(" setXIncludeAware " +
 552                 "is not supported on this JAXP" +
 553                 " implementation or earlier: " + this.getClass());
 554         }
 555     }
 556 
 557     /**
 558      * <p>Get state of XInclude processing.</p>
 559      *
 560      * @return current state of XInclude processing
 561      *
 562      * @throws UnsupportedOperationException When implementation does not
 563      *   override this method.
 564      *
 565      * @since 1.5
 566      */
 567     public boolean isXIncludeAware() {
 568         throw new UnsupportedOperationException(
 569             "This parser does not support specification \""
 570             + this.getClass().getPackage().getSpecificationTitle()
 571             + "\" version \""
 572             + this.getClass().getPackage().getSpecificationVersion()
 573             + "\""
 574             );
 575     }
 576 }