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
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  23  * questions.
  24  */
  25 
  26 package javax.xml.bind;
  27 
  28 import org.w3c.dom.Node;
  29 
  30 import java.util.Collections;
  31 import java.util.Map;
  32 import java.util.Properties;
  33 import java.io.IOException;
  34 import java.io.InputStream;
  35 
  36 /**
  37  * <p>
  38  * The <tt>JAXBContext</tt> class provides the client's entry point to the
  39  * JAXB API. It provides an abstraction for managing the XML/Java binding
  40  * information necessary to implement the JAXB binding framework operations:
  41  * unmarshal, marshal and validate.
  42  *
  43  * <p>A client application normally obtains new instances of this class using
  44  * one of these two styles for newInstance methods, although there are other
  45  * specialized forms of the method available:
  46  *
  47  * <ul>
  48  *   <li>{@link #newInstance(String,ClassLoader) JAXBContext.newInstance( "com.acme.foo:com.acme.bar" )} <br>
  49  *   The JAXBContext instance is initialized from a list of colon
  50  *   separated Java package names. Each java package contains
  51  *   JAXB mapped classes, schema-derived classes and/or user annotated
  52  *   classes. Additionally, the java package may contain JAXB package annotations
  53  *   that must be processed. (see JLS, Section 7.4.1 "Named Packages").
  54  *   </li>
  55  *   <li>{@link #newInstance(Class...) JAXBContext.newInstance( com.acme.foo.Foo.class )} <br>
  56  *    The JAXBContext instance is initialized with class(es)
  57  *    passed as parameter(s) and classes that are statically reachable from
  58  *    these class(es). See {@link #newInstance(Class...)} for details.
  59  *   </li>
  60  * </ul>
  61  *
  62  * <p>
  63  * <i><B>SPEC REQUIREMENT:</B> the provider must supply an implementation
  64  * class containing the following method signatures:</i>
  65  *
  66  * <pre>{@code
  67  * public static JAXBContext createContext( String contextPath, ClassLoader classLoader, Map<String,Object> properties ) throws JAXBException
  68  * public static JAXBContext createContext( Class[] classes, Map<String,Object> properties ) throws JAXBException
  69  * }</pre>
  70  *
  71  * <p><i>
  72  * The following JAXB 1.0 requirement is only required for schema to
  73  * java interface/implementation binding. It does not apply to JAXB annotated
  74  * classes. JAXB Providers must generate a <tt>jaxb.properties</tt> file in
  75  * each package containing schema derived classes.  The property file must
  76  * contain a property named <tt>javax.xml.bind.context.factory</tt> whose
  77  * value is the name of the class that implements the <tt>createContext</tt>
  78  * APIs.</i>
  79  *
  80  * <p><i>
  81  * The class supplied by the provider does not have to be assignable to
  82  * <tt>javax.xml.bind.JAXBContext</tt>, it simply has to provide a class that
  83  * implements the <tt>createContext</tt> APIs.</i>
  84  *
  85  * <p><i>
  86  * In addition, the provider must call the
  87  * {@link DatatypeConverter#setDatatypeConverter(DatatypeConverterInterface)
  88  * DatatypeConverter.setDatatypeConverter} api prior to any client
  89  * invocations of the marshal and unmarshal methods.  This is necessary to
  90  * configure the datatype converter that will be used during these operations.</i>
  91  *
  92  * <a name="Unmarshalling"></a>
  93  * <h3>Unmarshalling</h3>
  94  * <p>
  95  * The {@link Unmarshaller} class provides the client application the ability
  96  * to convert XML data into a tree of Java content objects.
  97  * The unmarshal method allows for
  98  * any global XML element declared in the schema to be unmarshalled as
  99  * the root of an instance document.
 100  * Additionally, the unmarshal method allows for an unrecognized root element that
 101  * has  an xsi:type attribute's value that references a type definition declared in
 102  * the schema  to be unmarshalled as the root of an instance document.
 103  * The <tt>JAXBContext</tt> object
 104  * allows the merging of global elements and type definitions across a set of schemas (listed
 105  * in the <tt>contextPath</tt>). Since each schema in the schema set can belong
 106  * to distinct namespaces, the unification of schemas to an unmarshalling
 107  * context should be namespace independent.  This means that a client
 108  * application is able to unmarshal XML documents that are instances of
 109  * any of the schemas listed in the <tt>contextPath</tt>.  For example:
 110  *
 111  * <pre>
 112  *        JAXBContext jc = JAXBContext.newInstance( "com.acme.foo:com.acme.bar" );
 113  *        Unmarshaller u = jc.createUnmarshaller();
 114  *        FooObject fooObj = (FooObject)u.unmarshal( new File( "foo.xml" ) ); // ok
 115  *        BarObject barObj = (BarObject)u.unmarshal( new File( "bar.xml" ) ); // ok
 116  *        BazObject bazObj = (BazObject)u.unmarshal( new File( "baz.xml" ) ); // error, "com.acme.baz" not in contextPath
 117  * </pre>
 118  *
 119  * <p>
 120  * The client application may also generate Java content trees explicitly rather
 121  * than unmarshalling existing XML data.  For all JAXB-annotated value classes,
 122  * an application can create content using constructors.
 123  * For schema-derived interface/implementation classes and for the
 124  * creation of elements that are not bound to a JAXB-annotated
 125  * class, an application needs to have access and knowledge about each of
 126  * the schema derived <tt> ObjectFactory</tt> classes that exist in each of
 127  * java packages contained in the <tt>contextPath</tt>.  For each schema
 128  * derived java class, there is a static factory method that produces objects
 129  * of that type.  For example,
 130  * assume that after compiling a schema, you have a package <tt>com.acme.foo</tt>
 131  * that contains a schema derived interface named <tt>PurchaseOrder</tt>.  In
 132  * order to create objects of that type, the client application would use the
 133  * factory method like this:
 134  *
 135  * <pre>
 136  *       com.acme.foo.PurchaseOrder po =
 137  *           com.acme.foo.ObjectFactory.createPurchaseOrder();
 138  * </pre>
 139  *
 140  * <p>
 141  * Once the client application has an instance of the the schema derived object,
 142  * it can use the mutator methods to set content on it.
 143  *
 144  * <p>
 145  * For more information on the generated <tt>ObjectFactory</tt> classes, see
 146  * Section 4.2 <i>Java Package</i> of the specification.
 147  *
 148  * <p>
 149  * <i><B>SPEC REQUIREMENT:</B> the provider must generate a class in each
 150  * package that contains all of the necessary object factory methods for that
 151  * package named ObjectFactory as well as the static
 152  * <tt>newInstance( javaContentInterface )</tt> method</i>
 153  *
 154  * <h3>Marshalling</h3>
 155  * <p>
 156  * The {@link Marshaller} class provides the client application the ability
 157  * to convert a Java content tree back into XML data.  There is no difference
 158  * between marshalling a content tree that is created manually using the factory
 159  * methods and marshalling a content tree that is the result an <tt>unmarshal
 160  * </tt> operation.  Clients can marshal a java content tree back to XML data
 161  * to a <tt>java.io.OutputStream</tt> or a <tt>java.io.Writer</tt>.  The
 162  * marshalling process can alternatively produce SAX2 event streams to a
 163  * registered <tt>ContentHandler</tt> or produce a DOM Node object.
 164  * Client applications have control over the output encoding as well as
 165  * whether or not to marshal the XML data as a complete document or
 166  * as a fragment.
 167  *
 168  * <p>
 169  * Here is a simple example that unmarshals an XML document and then marshals
 170  * it back out:
 171  *
 172  * <pre>
 173  *        JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );
 174  *
 175  *        // unmarshal from foo.xml
 176  *        Unmarshaller u = jc.createUnmarshaller();
 177  *        FooObject fooObj = (FooObject)u.unmarshal( new File( "foo.xml" ) );
 178  *
 179  *        // marshal to System.out
 180  *        Marshaller m = jc.createMarshaller();
 181  *        m.marshal( fooObj, System.out );
 182  * </pre>
 183  *
 184  *
 185  * <h3>Validation</h3>
 186  * <p>
 187  * Validation has been changed significantly since JAXB 1.0.  The {@link Validator}
 188  * class has been deprecated and made optional.  This means that you are advised
 189  * not to use this class and, in fact, it may not even be available depending on
 190  * your JAXB provider.  JAXB 1.0 client applications that rely on <tt>Validator</tt>
 191  * will still work properly when deployed with the JAXB 1.0 runtime system.
 192  *
 193  * In JAXB 2.0, the {@link Unmarshaller} has included convenince methods that expose
 194  * the JAXP 1.3 {@link javax.xml.validation} framework.  Please refer to the
 195  * {@link Unmarshaller#setSchema(javax.xml.validation.Schema)} API for more
 196  * information.
 197  *
 198  *
 199  * <h3>JAXB Runtime Binding Framework Compatibility</h3>
 200  * <p>
 201  * The following JAXB 1.0 restriction only applies to binding schema to
 202  * interfaces/implementation classes.
 203  * Since this binding does not require a common runtime system, a JAXB
 204  * client application must not attempt to mix runtime objects (<tt>JAXBContext,
 205  * Marshaller</tt>, etc. ) from different providers.  This does not
 206  * mean that the client application isn't portable, it simply means that a
 207  * client has to use a runtime system provided by the same provider that was
 208  * used to compile the schema.
 209  *
 210  *
 211  * <h3>Discovery of JAXB implementation</h3>
 212  * <p>
 213  * When one of the <tt>newInstance</tt> methods is called, a JAXB implementation is discovered
 214  * by the following steps.
 215  *
 216  * <ol>

 217  * <li>
 218  * For each package/class explicitly passed in to the {@link #newInstance} method, in the order they are specified,
 219  * <tt>jaxb.properties</tt> file is looked up in its package, by using the associated classloader &mdash;
 220  * this is {@link Class#getClassLoader() the owner class loader} for a {@link Class} argument, and for a package
 221  * the specified {@link ClassLoader}.
 222  *
 223  * <p>
 224  * If such a file is discovered, it is {@link Properties#load(InputStream) loaded} as a property file, and
 225  * the value of the {@link #JAXB_CONTEXT_FACTORY} key will be assumed to be the provider factory class.
 226  * This class is then loaded by the associated classloader discussed above.
 227  *
 228  * <p>
 229  * This phase of the look up allows some packages to force the use of a certain JAXB implementation.
 230  * (For example, perhaps the schema compiler has generated some vendor extension in the code.)
 231  *
 232  * <li>
 233  * If the system property {@link #JAXB_CONTEXT_FACTORY} exists, then its value is assumed to be the provider
 234  * factory class. This phase of the look up enables per-JVM override of the JAXB implementation.
 235  *
 236  * <li>
 237  * Look for <tt>/META-INF/services/javax.xml.bind.JAXBContext</tt> file in the associated classloader.
 238  * This file follows the standard service descriptor convention, and if such a file exists, its content
 239  * is assumed to be the provider factory class. This phase of the look up is for automatic discovery.
 240  * It allows users to just put a JAXB implementation in a classpath and use it without any furhter configuration.


























 241  *
 242  * <li>
 243  * Finally, if all the steps above fail, then the rest of the look up is unspecified. That said,
 244  * the recommended behavior is to simply look for some hard-coded platform default JAXB implementation.
 245  * This phase of the look up is so that JavaSE can have its own JAXB implementation as the last resort.
 246  * </ol>
 247  *
 248  * <p>
 249  * Once the provider factory class is discovered, its
 250  * <tt>public static JAXBContext createContext(String,ClassLoader,Map)</tt> method
 251  * (see {@link #newInstance(String, ClassLoader, Map)} for the parameter semantics.)
 252  * or <tt>public static JAXBContext createContet(Class[],Map)</tt> method
 253  * (see {@link #newInstance(Class[], Map)} for the parameter semantics) are invoked
 254  * to create a {@link JAXBContext}.
 255  *
 256  * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li><li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li><li>Joe Fialli, Sun Microsystems, Inc.</li></ul>













 257  * @see Marshaller
 258  * @see Unmarshaller
 259  * @see <a href="http://docs.oracle.com/javase/specs/jls/se7/html/jls-7.html#jls-7.4.1">S 7.4.1 "Named Packages" in Java Language Specification</a>


 260  * @since 1.6, JAXB 1.0
 261  */
 262 public abstract class JAXBContext {
 263 
 264     /**
 265      * The name of the property that contains the name of the class capable
 266      * of creating new <tt>JAXBContext</tt> objects.
 267      */
 268     public static final String JAXB_CONTEXT_FACTORY =
 269         "javax.xml.bind.context.factory";
 270 
 271 
 272     protected JAXBContext() {
 273     }
 274 
 275 
 276     /**
 277      * <p>
 278      * Obtain a new instance of a <tt>JAXBContext</tt> class.
 279      *
 280      * <p>
 281      * This is a convenience method to invoke the
 282      * {@link #newInstance(String,ClassLoader)} method with
 283      * the context class loader of the current thread.
 284      *
 285      * @throws JAXBException if an error was encountered while creating the
 286      *                       <tt>JAXBContext</tt> such as
 287      * <ol>
 288      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>
 289      *   <li>an ambiguity among global elements contained in the contextPath</li>
 290      *   <li>failure to locate a value for the context factory provider property</li>
 291      *   <li>mixing schema derived packages from different providers on the same contextPath</li>
 292      * </ol>
 293      */
 294     public static JAXBContext newInstance( String contextPath )
 295         throws JAXBException {
 296 
 297         //return newInstance( contextPath, JAXBContext.class.getClassLoader() );
 298         return newInstance( contextPath, getContextClassLoader());
 299     }
 300 
 301     /**
 302      * <p>
 303      * Obtain a new instance of a <tt>JAXBContext</tt> class.
 304      *
 305      * <p>
 306      * The client application must supply a context path which is a list of
 307      * colon (':', \u005Cu003A) separated java package names that contain
 308      * schema-derived classes and/or fully qualified JAXB-annotated classes.
 309      * Schema-derived
 310      * code is registered with the JAXBContext by the
 311      * ObjectFactory.class generated per package.
 312      * Alternatively than being listed in the context path, programmer
 313      * annotated JAXB mapped classes can be listed in a
 314      * <tt>jaxb.index</tt> resource file, format described below.
 315      * Note that a java package can contain both schema-derived classes and
 316      * user annotated JAXB classes. Additionally, the java package may
 317      * contain JAXB package annotations  that must be processed. (see JLS,
 318      * Section 7.4.1 "Named Packages").
 319      * </p>
 320      *
 321      * <p>
 322      * Every package listed on the contextPath must meet <b>one or both</b> of the
 323      * following conditions otherwise a <tt>JAXBException</tt> will be thrown:
 324      * </p>
 325      * <ol>
 326      *   <li>it must contain ObjectFactory.class</li>
 327      *   <li>it must contain jaxb.index</li>
 328      * </ol>
 329      *
 330      * <p>
 331      * <b>Format for jaxb.index</b>
 332      * <p>
 333      * The file contains a newline-separated list of class names.
 334      * Space and tab characters, as well as blank
 335      * lines, are ignored. The comment character
 336      * is '#' (0x23); on each line all characters following the first comment
 337      * character are ignored. The file must be encoded in UTF-8. Classes that
 338      * are reachable, as defined in {@link #newInstance(Class...)}, from the
 339      * listed classes are also registered with JAXBContext.
 340      * <p>
 341      * Constraints on class name occuring in a <tt>jaxb.index</tt> file are:
 342      * <ul>
 343      *   <li>Must not end with ".class".</li>
 344      *   <li>Class names are resolved relative to package containing
 345      *       <tt>jaxb.index</tt> file. Only classes occuring directly in package
 346      *       containing <tt>jaxb.index</tt> file are allowed.</li>
 347      *   <li>Fully qualified class names are not allowed.
 348      *       A qualified class name,relative to current package,
 349      *       is only allowed to specify a nested or inner class.</li>
 350      * </ul>
 351      *
 352      * <p>
 353      * To maintain compatibility with JAXB 1.0 schema to java
 354      * interface/implementation binding, enabled by schema customization
 355      * <tt>{@literal <jaxb:globalBindings valueClass="false">}</tt>,
 356      * the JAXB provider will ensure that each package on the context path
 357      * has a <tt>jaxb.properties</tt> file which contains a value for the
 358      * <tt>javax.xml.bind.context.factory</tt> property and that all values
 359      * resolve to the same provider.  This requirement does not apply to
 360      * JAXB annotated classes.
 361      *
 362      * <p>
 363      * If there are any global XML element name collisions across the various
 364      * packages listed on the <tt>contextPath</tt>, a <tt>JAXBException</tt>
 365      * will be thrown.
 366      *
 367      * <p>
 368      * Mixing generated interface/impl bindings from multiple JAXB Providers
 369      * in the same context path may result in a <tt>JAXBException</tt>
 370      * being thrown.
 371      *
 372      * <p>
 373      * The steps involved in discovering the JAXB implementation is discussed in the class javadoc.
 374      *
 375      * @param contextPath list of java package names that contain schema
 376      *                    derived class and/or java to schema (JAXB-annotated)
 377      *                    mapped classes
 378      * @param classLoader
 379      *      This class loader will be used to locate the implementation
 380      *      classes.
 381      *
 382      * @return a new instance of a <tt>JAXBContext</tt>
 383      * @throws JAXBException if an error was encountered while creating the
 384      *                       <tt>JAXBContext</tt> such as
 385      * <ol>
 386      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>
 387      *   <li>an ambiguity among global elements contained in the contextPath</li>
 388      *   <li>failure to locate a value for the context factory provider property</li>
 389      *   <li>mixing schema derived packages from different providers on the same contextPath</li>
 390      * </ol>
 391      */
 392     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader ) throws JAXBException {
 393 
 394         return newInstance(contextPath,classLoader,Collections.<String,Object>emptyMap());
 395     }
 396 
 397     /**
 398      * <p>
 399      * Obtain a new instance of a <tt>JAXBContext</tt> class.
 400      *
 401      * <p>
 402      * This is mostly the same as {@link JAXBContext#newInstance(String, ClassLoader)},
 403      * but this version allows you to pass in provider-specific properties to configure
 404      * the instantiation of {@link JAXBContext}.
 405      *
 406      * <p>
 407      * The interpretation of properties is up to implementations. Implementations should
 408      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.
 409      *
 410      * @param contextPath list of java package names that contain schema derived classes
 411      * @param classLoader
 412      *      This class loader will be used to locate the implementation classes.
 413      * @param properties
 414      *      provider-specific properties. Can be null, which means the same thing as passing
 415      *      in an empty map.
 416      *
 417      * @return a new instance of a <tt>JAXBContext</tt>
 418      * @throws JAXBException if an error was encountered while creating the
 419      *                       <tt>JAXBContext</tt> such as
 420      * <ol>
 421      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>
 422      *   <li>an ambiguity among global elements contained in the contextPath</li>
 423      *   <li>failure to locate a value for the context factory provider property</li>
 424      *   <li>mixing schema derived packages from different providers on the same contextPath</li>
 425      * </ol>
 426      * @since 1.6, JAXB 2.0
 427      */
 428     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader, Map<String,?>  properties  )
 429         throws JAXBException {

 430 
 431         return ContextFinder.find(
 432                         /* The default property name according to the JAXB spec */
 433                         JAXB_CONTEXT_FACTORY,
 434 
 435                         /* the context path supplied by the client app */
 436                         contextPath,
 437 
 438                         /* class loader to be used */
 439                         classLoader,
 440                         properties );
 441     }
 442 
 443 // TODO: resurrect this once we introduce external annotations
 444 //    /**
 445 //     * <p>
 446 //     * Obtain a new instance of a <tt>JAXBContext</tt> class.
 447 //     *
 448 //     * <p>
 449 //     * The client application must supply a list of classes that the new
 450 //     * context object needs to recognize.
 451 //     *
 452 //     * Not only the new context will recognize all the classes specified,
 453 //     * but it will also recognize any classes that are directly/indirectly
 454 //     * referenced statically from the specified classes.
 455 //     *
 456 //     * For example, in the following Java code, if you do
 457 //     * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}
 458 //     * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt>:
 459 //     * <pre>
 460 //     * class Foo {
 461 //     *      Bar b;
 462 //     * }
 463 //     * class Bar { int x; }
 464 //     * class Zot extends Bar { int y; }
 465 //     * </pre>
 466 //     *
 467 //     * Therefore, a typical client application only needs to specify the
 468 //     * top-level classes, but it needs to be careful.
 469 //     *
 470 //     * TODO: if we are to define other mechanisms, refer to them.
 471 //     *
 472 //     * @param externalBindings
 473 //     *      list of external binding files. Can be null or empty if none is used.
 474 //     *      when specified, those files determine how the classes are bound.
 475 //     *
 476 //     * @param classesToBeBound
 477 //     *      list of java classes to be recognized by the new {@link JAXBContext}.
 478 //     *      Can be empty, in which case a {@link JAXBContext} that only knows about
 479 //     *      spec-defined classes will be returned.
 480 //     *
 481 //     * @return
 482 //     *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.
 483 //     *
 484 //     * @throws JAXBException
 485 //     *      if an error was encountered while creating the
 486 //     *      <tt>JAXBContext</tt>, such as (but not limited to):
 487 //     * <ol>
 488 //     *  <li>No JAXB implementation was discovered
 489 //     *  <li>Classes use JAXB annotations incorrectly
 490 //     *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 491 //     *  <li>Specified external bindings are incorrect
 492 //     *  <li>The JAXB implementation was unable to locate
 493 //     *      provider-specific out-of-band information (such as additional
 494 //     *      files generated at the development time.)
 495 //     * </ol>
 496 //     *
 497 //     * @throws IllegalArgumentException
 498 //     *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})
 499 //     *
 500 //     * @since JAXB 2.0
 501 //     */
 502 //    public static JAXBContext newInstance( Source[] externalBindings, Class... classesToBeBound )
 503 //        throws JAXBException {
 504 //
 505 //        // empty class list is not an error, because the context will still include
 506 //        // spec-specified classes like String and Integer.
 507 //        // if(classesToBeBound.length==0)
 508 //        //    throw new IllegalArgumentException();
 509 //
 510 //        // but it is an error to have nulls in it.
 511 //        for( int i=classesToBeBound.length-1; i>=0; i-- )
 512 //            if(classesToBeBound[i]==null)
 513 //                throw new IllegalArgumentException();
 514 //
 515 //        return ContextFinder.find(externalBindings,classesToBeBound);
 516 //    }
 517 
 518     /**
 519      * <p>
 520      * Obtain a new instance of a <tt>JAXBContext</tt> class.
 521      *
 522      * <p>
 523      * The client application must supply a list of classes that the new
 524      * context object needs to recognize.
 525      *
 526      * Not only the new context will recognize all the classes specified,
 527      * but it will also recognize any classes that are directly/indirectly
 528      * referenced statically from the specified classes. Subclasses of
 529      * referenced classes nor <tt>@XmlTransient</tt> referenced classes
 530      * are not registered with JAXBContext.
 531      *
 532      * For example, in the following Java code, if you do
 533      * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}
 534      * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt> or <tt>FooBar</tt>:
 535      * <pre>
 536      * class Foo {
 537      *      @XmlTransient FooBar c;
 538      *      Bar b;
 539      * }
 540      * class Bar { int x; }
 541      * class Zot extends Bar { int y; }
 542      * class FooBar { }
 543      * </pre>
 544      *
 545      * Therefore, a typical client application only needs to specify the
 546      * top-level classes, but it needs to be careful.
 547      *
 548      * <p>
 549      * Note that for each java package registered with JAXBContext,
 550      * when the optional package annotations exist, they must be processed.
 551      * (see JLS, Section 7.4.1 "Named Packages").
 552      *
 553      * <p>
 554      * The steps involved in discovering the JAXB implementation is discussed in the class javadoc.
 555      *
 556      * @param classesToBeBound
 557      *      list of java classes to be recognized by the new {@link JAXBContext}.
 558      *      Can be empty, in which case a {@link JAXBContext} that only knows about
 559      *      spec-defined classes will be returned.
 560      *
 561      * @return
 562      *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.
 563      *
 564      * @throws JAXBException
 565      *      if an error was encountered while creating the
 566      *      <tt>JAXBContext</tt>, such as (but not limited to):
 567      * <ol>
 568      *  <li>No JAXB implementation was discovered
 569      *  <li>Classes use JAXB annotations incorrectly
 570      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 571      *  <li>The JAXB implementation was unable to locate
 572      *      provider-specific out-of-band information (such as additional
 573      *      files generated at the development time.)
 574      * </ol>
 575      *
 576      * @throws IllegalArgumentException
 577      *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})
 578      *
 579      * @since 1.6, JAXB 2.0
 580      */
 581     public static JAXBContext newInstance( Class... classesToBeBound )
 582         throws JAXBException {
 583 
 584         return newInstance(classesToBeBound,Collections.<String,Object>emptyMap());
 585     }
 586 
 587     /**
 588      * <p>
 589      * Obtain a new instance of a <tt>JAXBContext</tt> class.
 590      *
 591      * <p>
 592      * An overloading of {@link JAXBContext#newInstance(Class...)}
 593      * to configure 'properties' for this instantiation of {@link JAXBContext}.
 594      *
 595      * <p>
 596      * The interpretation of properties is up to implementations. Implementations should
 597      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.
 598      *
 599      * @param classesToBeBound
 600      *      list of java classes to be recognized by the new {@link JAXBContext}.
 601      *      Can be empty, in which case a {@link JAXBContext} that only knows about
 602      *      spec-defined classes will be returned.
 603      * @param properties
 604      *      provider-specific properties. Can be null, which means the same thing as passing
 605      *      in an empty map.
 606      *
 607      * @return
 608      *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.
 609      *
 610      * @throws JAXBException
 611      *      if an error was encountered while creating the
 612      *      <tt>JAXBContext</tt>, such as (but not limited to):
 613      * <ol>
 614      *  <li>No JAXB implementation was discovered
 615      *  <li>Classes use JAXB annotations incorrectly
 616      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 617      *  <li>The JAXB implementation was unable to locate
 618      *      provider-specific out-of-band information (such as additional
 619      *      files generated at the development time.)
 620      * </ol>
 621      *
 622      * @throws IllegalArgumentException
 623      *      if the parameter contains {@code null} (i.e., {@code newInstance(null,someMap);})
 624      *
 625      * @since 1.6, JAXB 2.0
 626      */
 627     public static JAXBContext newInstance( Class[] classesToBeBound, Map<String,?> properties )
 628         throws JAXBException {
 629 
 630         if (classesToBeBound == null) {
 631                 throw new IllegalArgumentException();
 632         }
 633 
 634         // but it is an error to have nulls in it.
 635         for (int i = classesToBeBound.length - 1; i >= 0; i--) {
 636             if (classesToBeBound[i] == null) {
 637                 throw new IllegalArgumentException();
 638             }
 639         }
 640 
 641         return ContextFinder.find(classesToBeBound,properties);
 642     }
 643 
 644     /**
 645      * Create an <tt>Unmarshaller</tt> object that can be used to convert XML
 646      * data into a java content tree.
 647      *
 648      * @return an <tt>Unmarshaller</tt> object
 649      *
 650      * @throws JAXBException if an error was encountered while creating the
 651      *                       <tt>Unmarshaller</tt> object
 652      */
 653     public abstract Unmarshaller createUnmarshaller() throws JAXBException;
 654 
 655 
 656     /**
 657      * Create a <tt>Marshaller</tt> object that can be used to convert a
 658      * java content tree into XML data.
 659      *
 660      * @return a <tt>Marshaller</tt> object
 661      *
 662      * @throws JAXBException if an error was encountered while creating the
 663      *                       <tt>Marshaller</tt> object
 664      */
 665     public abstract Marshaller createMarshaller() throws JAXBException;
 666 
 667 
 668     /**
 669      * {@link Validator} has been made optional and deprecated in JAXB 2.0.  Please
 670      * refer to the javadoc for {@link Validator} for more detail.
 671      * <p>
 672      * Create a <tt>Validator</tt> object that can be used to validate a
 673      * java content tree against its source schema.
 674      *
 675      * @return a <tt>Validator</tt> object
 676      *
 677      * @throws JAXBException if an error was encountered while creating the
 678      *                       <tt>Validator</tt> object
 679      * @deprecated since JAXB2.0
 680      */
 681     public abstract Validator createValidator() throws JAXBException;
 682 
 683     /**
 684      * Creates a <tt>Binder</tt> object that can be used for
 685      * associative/in-place unmarshalling/marshalling.
 686      *
 687      * @param domType select the DOM API to use by passing in its DOM Node class.
 688      *
 689      * @return always a new valid <tt>Binder</tt> object.
 690      *
 691      * @throws UnsupportedOperationException
 692      *      if DOM API corresponding to <tt>domType</tt> is not supported by
 693      *      the implementation.
 694      *
 695      * @since 1.6, JAXB 2.0
 696      */
 697     public <T> Binder<T> createBinder(Class<T> domType) {
 698         // to make JAXB 1.0 implementations work, this method must not be
 699         // abstract
 700         throw new UnsupportedOperationException();
 701     }
 702 
 703     /**
 704      * Creates a <tt>Binder</tt> for W3C DOM.
 705      *
 706      * @return always a new valid <tt>Binder</tt> object.
 707      *
 708      * @since 1.6, JAXB 2.0
 709      */
 710     public Binder<Node> createBinder() {
 711         return createBinder(Node.class);
 712     }
 713 
 714     /**
 715      * Creates a <tt>JAXBIntrospector</tt> object that can be used to
 716      * introspect JAXB objects.
 717      *
 718      * @return
 719      *      always return a non-null valid <tt>JAXBIntrospector</tt> object.
 720      *
 721      * @throws UnsupportedOperationException
 722      *      Calling this method on JAXB 1.0 implementations will throw
 723      *      an UnsupportedOperationException.
 724      *
 725      * @since 1.6, JAXB 2.0
 726      */
 727     public JAXBIntrospector createJAXBIntrospector() {
 728         // to make JAXB 1.0 implementations work, this method must not be
 729         // abstract
 730         throw new UnsupportedOperationException();
 731     }
 732 
 733     /**
 734      * Generates the schema documents for this context.
 735      *
 736      * @param outputResolver
 737      *      this object controls the output to which schemas
 738      *      will be sent.
 739      *
 740      * @throws IOException
 741      *      if {@link SchemaOutputResolver} throws an {@link IOException}.
 742      *
 743      * @throws UnsupportedOperationException
 744      *      Calling this method on JAXB 1.0 implementations will throw
 745      *      an UnsupportedOperationException.
 746      *
 747      * @since 1.6, JAXB 2.0
 748      */
 749     public void generateSchema(SchemaOutputResolver outputResolver) throws IOException  {
 750         // to make JAXB 1.0 implementations work, this method must not be
 751         // abstract
 752         throw new UnsupportedOperationException();
 753     }
 754 
 755     private static ClassLoader getContextClassLoader() {
 756         if (System.getSecurityManager() == null) {
 757             return Thread.currentThread().getContextClassLoader();
 758         } else {
 759             return (ClassLoader) java.security.AccessController.doPrivileged(
 760                     new java.security.PrivilegedAction() {
 761                         public java.lang.Object run() {
 762                             return Thread.currentThread().getContextClassLoader();
 763                         }
 764                     });
 765         }
 766     }
 767 
 768 }
--- EOF ---