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  *
  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 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  * @since 1.4
  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 using the {@linkplain
  86      * java.util.ServiceLoader#load(java.lang.Class) default loading mechanism}:
  87      * the service-provider loading facility will use the {@linkplain
  88      * java.lang.Thread#getContextClassLoader() current thread's context class loader}
  89      * to attempt to load the service. If the context class
  90      * loader is null, the {@linkplain
  91      * ClassLoader#getSystemClassLoader() system class loader} will be used.
  92      * </li>
  93      * <li>
  94      * Otherwise, the system-default implementation is returned.
  95      * </li>
  96      * </ul>
  97      *
  98      * Once an application has obtained a reference to a
  99      * <code>DocumentBuilderFactory</code> it can use the factory to
 100      * configure and obtain parser instances.
 101      *
 102      *
 103      * <h2>Tip for Trouble-shooting</h2>
 104      * <p>Setting the <code>jaxp.debug</code> system property will cause
 105      * this method to print a lot of debug messages
 106      * to <code>System.err</code> about what it is doing and where it is looking at.</p>
 107      *
 108      * <p> If you have problems loading {@link DocumentBuilder}s, try:</p>
 109      * <pre>
 110      * java -Djaxp.debug=1 YourProgram ....
 111      * </pre>
 112      *
 113      * @return New instance of a <code>DocumentBuilderFactory</code>
 114      *
 115      * @throws FactoryConfigurationError in case of {@linkplain
 116      * java.util.ServiceConfigurationError service configuration error} or if
 117      * the implementation is not available or cannot be instantiated.
 118      */
 119     public static DocumentBuilderFactory newInstance() {
 120         return FactoryFinder.find(
 121                 /* The default property name according to the JAXP spec */
 122                 DocumentBuilderFactory.class, // "javax.xml.parsers.DocumentBuilderFactory"
 123                 /* The fallback implementation class name */
 124                 "com.sun.org.apache.xerces.internal.jaxp.DocumentBuilderFactoryImpl");
 125     }
 126 
 127     /**
 128      * <p>Obtain a new instance of a <code>DocumentBuilderFactory</code> from class name.
 129      * This function is useful when there are multiple providers in the classpath.
 130      * It gives more control to the application as it can specify which provider
 131      * should be loaded.</p>
 132      *
 133      * <p>Once an application has obtained a reference to a <code>DocumentBuilderFactory</code>
 134      * it can use the factory to configure and obtain parser instances.</p>
 135      *
 136      *
 137      * <h2>Tip for Trouble-shooting</h2>
 138      * <p>Setting the <code>jaxp.debug</code> system property will cause
 139      * this method to print a lot of debug messages
 140      * to <code>System.err</code> about what it is doing and where it is looking at.</p>
 141      *
 142      * <p> If you have problems try:</p>
 143      * <pre>
 144      * java -Djaxp.debug=1 YourProgram ....
 145      * </pre>
 146      *
 147      * @param factoryClassName fully qualified factory class name that provides implementation of <code>javax.xml.parsers.DocumentBuilderFactory</code>.
 148      *
 149      * @param classLoader <code>ClassLoader</code> used to load the factory class. If <code>null</code>
 150      *                     current <code>Thread</code>'s context classLoader is used to load the factory class.
 151      *
 152      * @return New instance of a <code>DocumentBuilderFactory</code>
 153      *
 154      * @throws FactoryConfigurationError if <code>factoryClassName</code> is <code>null</code>, or
 155      *                                   the factory class cannot be loaded, instantiated.
 156      *
 157      * @see #newInstance()
 158      *
 159      * @since 1.6
 160      */
 161     public static DocumentBuilderFactory newInstance(String factoryClassName, ClassLoader classLoader){
 162             //do not fallback if given classloader can't find the class, throw exception
 163             return FactoryFinder.newInstance(DocumentBuilderFactory.class,
 164                         factoryClassName, classLoader, false);
 165     }
 166 
 167     /**
 168      * Creates a new instance of a {@link javax.xml.parsers.DocumentBuilder}
 169      * using the currently configured parameters.
 170      *
 171      * @return A new instance of a DocumentBuilder.
 172      *
 173      * @throws ParserConfigurationException if a DocumentBuilder
 174      *   cannot be created which satisfies the configuration requested.
 175      */
 176 
 177     public abstract DocumentBuilder newDocumentBuilder()
 178         throws ParserConfigurationException;
 179 
 180 
 181     /**
 182      * Specifies that the parser produced by this code will
 183      * provide support for XML namespaces. By default the value of this is set
 184      * to <code>false</code>
 185      *
 186      * @param awareness true if the parser produced will provide support
 187      *                  for XML namespaces; false otherwise.
 188      */
 189 
 190     public void setNamespaceAware(boolean awareness) {
 191         this.namespaceAware = awareness;
 192     }
 193 
 194     /**
 195      * Specifies that the parser produced by this code will
 196      * validate documents as they are parsed. By default the value of this
 197      * is set to <code>false</code>.
 198      *
 199      * <p>
 200      * Note that "the validation" here means
 201      * <a href="http://www.w3.org/TR/REC-xml#proc-types">a validating
 202      * parser</a> as defined in the XML recommendation.
 203      * In other words, it essentially just controls the DTD validation.
 204      * (except the legacy two properties defined in JAXP 1.2.)
 205      * </p>
 206      *
 207      * <p>
 208      * To use modern schema languages such as W3C XML Schema or
 209      * RELAX NG instead of DTD, you can configure your parser to be
 210      * a non-validating parser by leaving the {@link #setValidating(boolean)}
 211      * method <code>false</code>, then use the {@link #setSchema(Schema)}
 212      * method to associate a schema to a parser.
 213      * </p>
 214      *
 215      * @param validating true if the parser produced will validate documents
 216      *                   as they are parsed; false otherwise.
 217      */
 218 
 219     public void setValidating(boolean validating) {
 220         this.validating = validating;
 221     }
 222 
 223     /**
 224      * Specifies that the parsers created by this  factory must eliminate
 225      * whitespace in element content (sometimes known loosely as
 226      * 'ignorable whitespace') when parsing XML documents (see XML Rec
 227      * 2.10). Note that only whitespace which is directly contained within
 228      * element content that has an element only content model (see XML
 229      * Rec 3.2.1) will be eliminated. Due to reliance on the content model
 230      * this setting requires the parser to be in validating mode. By default
 231      * the value of this is set to <code>false</code>.
 232      *
 233      * @param whitespace true if the parser created must eliminate whitespace
 234      *                   in the element content when parsing XML documents;
 235      *                   false otherwise.
 236      */
 237 
 238     public void setIgnoringElementContentWhitespace(boolean whitespace) {
 239         this.whitespace = whitespace;
 240     }
 241 
 242     /**
 243      * Specifies that the parser produced by this code will
 244      * expand entity reference nodes. By default the value of this is set to
 245      * <code>true</code>
 246      *
 247      * @param expandEntityRef true if the parser produced will expand entity
 248      *                        reference nodes; false otherwise.
 249      */
 250 
 251     public void setExpandEntityReferences(boolean expandEntityRef) {
 252         this.expandEntityRef = expandEntityRef;
 253     }
 254 
 255     /**
 256      * <p>Specifies that the parser produced by this code will
 257      * ignore comments. By default the value of this is set to <code>false
 258      * </code>.</p>
 259      *
 260      * @param ignoreComments <code>boolean</code> value to ignore comments during processing
 261      */
 262 
 263     public void setIgnoringComments(boolean ignoreComments) {
 264         this.ignoreComments = ignoreComments;
 265     }
 266 
 267     /**
 268      * Specifies that the parser produced by this code will
 269      * convert CDATA nodes to Text nodes and append it to the
 270      * adjacent (if any) text node. By default the value of this is set to
 271      * <code>false</code>
 272      *
 273      * @param coalescing  true if the parser produced will convert CDATA nodes
 274      *                    to Text nodes and append it to the adjacent (if any)
 275      *                    text node; false otherwise.
 276      */
 277 
 278     public void setCoalescing(boolean coalescing) {
 279         this.coalescing = coalescing;
 280     }
 281 
 282     /**
 283      * Indicates whether or not the factory is configured to produce
 284      * parsers which are namespace aware.
 285      *
 286      * @return  true if the factory is configured to produce parsers which
 287      *          are namespace aware; false otherwise.
 288      */
 289 
 290     public boolean isNamespaceAware() {
 291         return namespaceAware;
 292     }
 293 
 294     /**
 295      * Indicates whether or not the factory is configured to produce
 296      * parsers which validate the XML content during parse.
 297      *
 298      * @return  true if the factory is configured to produce parsers
 299      *          which validate the XML content during parse; false otherwise.
 300      */
 301 
 302     public boolean isValidating() {
 303         return validating;
 304     }
 305 
 306     /**
 307      * Indicates whether or not the factory is configured to produce
 308      * parsers which ignore ignorable whitespace in element content.
 309      *
 310      * @return  true if the factory is configured to produce parsers
 311      *          which ignore ignorable whitespace in element content;
 312      *          false otherwise.
 313      */
 314 
 315     public boolean isIgnoringElementContentWhitespace() {
 316         return whitespace;
 317     }
 318 
 319     /**
 320      * Indicates whether or not the factory is configured to produce
 321      * parsers which expand entity reference nodes.
 322      *
 323      * @return  true if the factory is configured to produce parsers
 324      *          which expand entity reference nodes; false otherwise.
 325      */
 326 
 327     public boolean isExpandEntityReferences() {
 328         return expandEntityRef;
 329     }
 330 
 331     /**
 332      * Indicates whether or not the factory is configured to produce
 333      * parsers which ignores comments.
 334      *
 335      * @return  true if the factory is configured to produce parsers
 336      *          which ignores comments; false otherwise.
 337      */
 338 
 339     public boolean isIgnoringComments() {
 340         return ignoreComments;
 341     }
 342 
 343     /**
 344      * Indicates whether or not the factory is configured to produce
 345      * parsers which converts CDATA nodes to Text nodes and appends it to
 346      * the adjacent (if any) Text node.
 347      *
 348      * @return  true if the factory is configured to produce parsers
 349      *          which converts CDATA nodes to Text nodes and appends it to
 350      *          the adjacent (if any) Text node; false otherwise.
 351      */
 352 
 353     public boolean isCoalescing() {
 354         return coalescing;
 355     }
 356 
 357     /**
 358      * Allows the user to set specific attributes on the underlying
 359      * implementation.
 360      * <p>
 361      * All implementations that implement JAXP 1.5 or newer are required to
 362      * support the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} and
 363      * {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_SCHEMA} properties.
 364      * </p>
 365      * <ul>
 366      *   <li>
 367      *      <p>
 368      *      Setting the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_DTD} property
 369      *      restricts the access to external DTDs, external Entity References to the
 370      *      protocols specified by the property.
 371      *      If access is denied during parsing due to the restriction of this property,
 372      *      {@link org.xml.sax.SAXException} will be thrown by the parse methods defined by
 373      *      {@link javax.xml.parsers.DocumentBuilder}.
 374      *      </p>
 375      *      <p>
 376      *      Setting the {@link javax.xml.XMLConstants#ACCESS_EXTERNAL_SCHEMA} property
 377      *      restricts the access to external Schema set by the schemaLocation attribute to
 378      *      the protocols specified by the property.  If access is denied during parsing
 379      *      due to the restriction of this property, {@link org.xml.sax.SAXException}
 380      *      will be thrown by the parse methods defined by
 381      *      {@link javax.xml.parsers.DocumentBuilder}.
 382      *      </p>
 383      *   </li>
 384      * </ul>
 385      *
 386      * @param name The name of the attribute.
 387      * @param value The value of the attribute.
 388      *
 389      * @throws IllegalArgumentException thrown if the underlying
 390      *   implementation doesn't recognize the attribute.
 391      */
 392     public abstract void setAttribute(String name, Object value)
 393                 throws IllegalArgumentException;
 394 
 395     /**
 396      * Allows the user to retrieve specific attributes on the underlying
 397      * implementation.
 398      *
 399      * @param name The name of the attribute.
 400      *
 401      * @return value The value of the attribute.
 402      *
 403      * @throws IllegalArgumentException thrown if the underlying
 404      *   implementation doesn't recognize the attribute.
 405      */
 406     public abstract Object getAttribute(String name)
 407                 throws IllegalArgumentException;
 408 
 409     /**
 410      * <p>Set a feature for this <code>DocumentBuilderFactory</code> and <code>DocumentBuilder</code>s created by this factory.</p>
 411      *
 412      * <p>
 413      * Feature names are fully qualified {@link java.net.URI}s.
 414      * Implementations may define their own features.
 415      * A {@link ParserConfigurationException} is thrown if this <code>DocumentBuilderFactory</code> or the
 416      * <code>DocumentBuilder</code>s it creates cannot support the feature.
 417      * It is possible for a <code>DocumentBuilderFactory</code> to expose a feature value but be unable to change its state.
 418      * </p>
 419      *
 420      * <p>
 421      * All implementations are required to support the {@link javax.xml.XMLConstants#FEATURE_SECURE_PROCESSING} feature.
 422      * When the feature is:</p>
 423      * <ul>
 424      *   <li>
 425      *     <code>true</code>: the implementation will limit XML processing to conform to implementation limits.
 426      *     Examples include entity expansion limits and XML Schema constructs that would consume large amounts of resources.
 427      *     If XML processing is limited for security reasons, it will be reported via a call to the registered
 428      *    {@link org.xml.sax.ErrorHandler#fatalError(SAXParseException exception)}.
 429      *     See {@link  DocumentBuilder#setErrorHandler(org.xml.sax.ErrorHandler errorHandler)}.
 430      *   </li>
 431      *   <li>
 432      *     <code>false</code>: the implementation will processing XML according to the XML specifications without
 433      *     regard to possible implementation limits.
 434      *   </li>
 435      * </ul>
 436      *
 437      * @param name Feature name.
 438      * @param value Is feature state <code>true</code> or <code>false</code>.
 439      *
 440      * @throws ParserConfigurationException if this <code>DocumentBuilderFactory</code> or the <code>DocumentBuilder</code>s
 441      *   it creates cannot support this feature.
 442      * @throws NullPointerException If the <code>name</code> parameter is null.
 443      * @since 1.5
 444      */
 445     public abstract void setFeature(String name, boolean value)
 446             throws ParserConfigurationException;
 447 
 448     /**
 449      * <p>Get the state of the named feature.</p>
 450      *
 451      * <p>
 452      * Feature names are fully qualified {@link java.net.URI}s.
 453      * Implementations may define their own features.
 454      * An {@link ParserConfigurationException} is thrown if this <code>DocumentBuilderFactory</code> or the
 455      * <code>DocumentBuilder</code>s it creates cannot support the feature.
 456      * It is possible for an <code>DocumentBuilderFactory</code> to expose a feature value but be unable to change its state.
 457      * </p>
 458      *
 459      * @param name Feature name.
 460      *
 461      * @return State of the named feature.
 462      *
 463      * @throws ParserConfigurationException if this <code>DocumentBuilderFactory</code>
 464      *   or the <code>DocumentBuilder</code>s it creates cannot support this feature.
 465      * @since 1.5
 466      */
 467     public abstract boolean getFeature(String name)
 468             throws ParserConfigurationException;
 469 
 470 
 471     /**
 472      * Gets the {@link Schema} object specified through
 473      * the {@link #setSchema(Schema schema)} method.
 474      *
 475      * @return
 476      *      the {@link Schema} object that was last set through
 477      *      the {@link #setSchema(Schema)} method, or null
 478      *      if the method was not invoked since a {@link DocumentBuilderFactory}
 479      *      is created.
 480      *
 481      * @throws UnsupportedOperationException When implementation does not
 482      *   override this method.
 483      *
 484      * @since 1.5
 485      */
 486     public Schema getSchema() {
 487         throw new UnsupportedOperationException(
 488             "This parser does not support specification \""
 489             + this.getClass().getPackage().getSpecificationTitle()
 490             + "\" version \""
 491             + this.getClass().getPackage().getSpecificationVersion()
 492             + "\""
 493             );
 494 
 495     }
 496 
 497     /**
 498      * <p>Set the {@link Schema} to be used by parsers created
 499      * from this factory.
 500      *
 501      * <p>
 502      * When a {@link Schema} is non-null, a parser will use a validator
 503      * created from it to validate documents before it passes information
 504      * down to the application.
 505      *
 506      * <p>When errors are found by the validator, the parser is responsible
 507      * to report them to the user-specified {@link org.xml.sax.ErrorHandler}
 508      * (or if the error handler is not set, ignore them or throw them), just
 509      * like any other errors found by the parser itself.
 510      * In other words, if the user-specified {@link org.xml.sax.ErrorHandler}
 511      * is set, it must receive those errors, and if not, they must be
 512      * treated according to the implementation specific
 513      * default error handling rules.
 514      *
 515      * <p>
 516      * A validator may modify the outcome of a parse (for example by
 517      * adding default values that were missing in documents), and a parser
 518      * is responsible to make sure that the application will receive
 519      * modified DOM trees.
 520      *
 521      * <p>
 522      * Initially, null is set as the {@link Schema}.
 523      *
 524      * <p>
 525      * This processing will take effect even if
 526      * the {@link #isValidating()} method returns <code>false</code>.
 527      *
 528      * <p>It is an error to use
 529      * the <code>http://java.sun.com/xml/jaxp/properties/schemaSource</code>
 530      * property and/or the <code>http://java.sun.com/xml/jaxp/properties/schemaLanguage</code>
 531      * property in conjunction with a {@link Schema} object.
 532      * Such configuration will cause a {@link ParserConfigurationException}
 533      * exception when the {@link #newDocumentBuilder()} is invoked.</p>
 534      *
 535      *
 536      * <h4>Note for implementors</h4>
 537      *
 538      * <p>
 539      * A parser must be able to work with any {@link Schema}
 540      * implementation. However, parsers and schemas are allowed
 541      * to use implementation-specific custom mechanisms
 542      * as long as they yield the result described in the specification.
 543      * </p>
 544      *
 545      * @param schema <code>Schema</code> to use or <code>null</code>
 546      *   to remove a schema.
 547      *
 548      * @throws UnsupportedOperationException When implementation does not
 549      *   override this method.
 550      *
 551      * @since 1.5
 552      */
 553     public void setSchema(Schema schema) {
 554         throw new UnsupportedOperationException(
 555             "This parser does not support specification \""
 556             + this.getClass().getPackage().getSpecificationTitle()
 557             + "\" version \""
 558             + this.getClass().getPackage().getSpecificationVersion()
 559             + "\""
 560             );
 561     }
 562 
 563 
 564 
 565     /**
 566      * <p>Set state of XInclude processing.</p>
 567      *
 568      * <p>If XInclude markup is found in the document instance, should it be
 569      * processed as specified in <a href="http://www.w3.org/TR/xinclude/">
 570      * XML Inclusions (XInclude) Version 1.0</a>.</p>
 571      *
 572      * <p>XInclude processing defaults to <code>false</code>.</p>
 573      *
 574      * @param state Set XInclude processing to <code>true</code> or
 575      *   <code>false</code>
 576      *
 577      * @throws UnsupportedOperationException When implementation does not
 578      *   override this method.
 579      *
 580      * @since 1.5
 581      */
 582     public void setXIncludeAware(final boolean state) {
 583         if (state) {
 584             throw new UnsupportedOperationException(" setXIncludeAware " +
 585                 "is not supported on this JAXP" +
 586                 " implementation or earlier: " + this.getClass());
 587         }
 588     }
 589 
 590     /**
 591      * <p>Get state of XInclude processing.</p>
 592      *
 593      * @return current state of XInclude processing
 594      *
 595      * @throws UnsupportedOperationException When implementation does not
 596      *   override this method.
 597      *
 598      * @since 1.5
 599      */
 600     public boolean isXIncludeAware() {
 601         throw new UnsupportedOperationException(
 602             "This parser does not support specification \""
 603             + this.getClass().getPackage().getSpecificationTitle()
 604             + "\" version \""
 605             + this.getClass().getPackage().getSpecificationVersion()
 606             + "\""
 607             );
 608     }
 609 }