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src/java.xml.bind/share/classes/javax/xml/bind/JAXBContext.java

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  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>


 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


 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:


 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


 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; }


 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      *


 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 }


  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><i>
  63  * The following JAXB 1.0 requirement is only required for schema to
  64  * java interface/implementation binding. It does not apply to JAXB annotated
  65  * classes. JAXB Providers must generate a <tt>jaxb.properties</tt> file in
  66  * each package containing schema derived classes.  The property file must
  67  * contain a property named <tt>javax.xml.bind.context.factory</tt> whose
  68  * value is the name of the class that implements the <tt>createContext</tt>
  69  * APIs.</i>
  70  *
  71  * <p><i>
  72  * The class supplied by the provider does not have to be assignable to
  73  * <tt>javax.xml.bind.JAXBContext</tt>, it simply has to provide a class that
  74  * implements the <tt>createContext</tt> APIs.</i>
  75  *
  76  * <p><i>
  77  * In addition, the provider must call the
  78  * {@link DatatypeConverter#setDatatypeConverter(DatatypeConverterInterface)
  79  * DatatypeConverter.setDatatypeConverter} api prior to any client
  80  * invocations of the marshal and unmarshal methods.  This is necessary to
  81  * configure the datatype converter that will be used during these operations.</i>


 120  * of that type.  For example,
 121  * assume that after compiling a schema, you have a package <tt>com.acme.foo</tt>
 122  * that contains a schema derived interface named <tt>PurchaseOrder</tt>.  In
 123  * order to create objects of that type, the client application would use the
 124  * factory method like this:
 125  *
 126  * <pre>
 127  *       com.acme.foo.PurchaseOrder po =
 128  *           com.acme.foo.ObjectFactory.createPurchaseOrder();
 129  * </pre>
 130  *
 131  * <p>
 132  * Once the client application has an instance of the the schema derived object,
 133  * it can use the mutator methods to set content on it.
 134  *
 135  * <p>
 136  * For more information on the generated <tt>ObjectFactory</tt> classes, see
 137  * Section 4.2 <i>Java Package</i> of the specification.
 138  *
 139  * <p>
 140  * <i>The provider must generate a class in each
 141  * package that contains all of the necessary object factory methods for that
 142  * package named ObjectFactory as well as the static
 143  * <tt>newInstance( javaContentInterface )</tt> method</i>
 144  *
 145  * <h3>Marshalling</h3>
 146  * <p>
 147  * The {@link Marshaller} class provides the client application the ability
 148  * to convert a Java content tree back into XML data.  There is no difference
 149  * between marshalling a content tree that is created manually using the factory
 150  * methods and marshalling a content tree that is the result an <tt>unmarshal
 151  * </tt> operation.  Clients can marshal a java content tree back to XML data
 152  * to a <tt>java.io.OutputStream</tt> or a <tt>java.io.Writer</tt>.  The
 153  * marshalling process can alternatively produce SAX2 event streams to a
 154  * registered <tt>ContentHandler</tt> or produce a DOM Node object.
 155  * Client applications have control over the output encoding as well as
 156  * whether or not to marshal the XML data as a complete document or
 157  * as a fragment.
 158  *
 159  * <p>
 160  * Here is a simple example that unmarshals an XML document and then marshals


 188  *
 189  *
 190  * <h3>JAXB Runtime Binding Framework Compatibility</h3>
 191  * <p>
 192  * The following JAXB 1.0 restriction only applies to binding schema to
 193  * interfaces/implementation classes.
 194  * Since this binding does not require a common runtime system, a JAXB
 195  * client application must not attempt to mix runtime objects (<tt>JAXBContext,
 196  * Marshaller</tt>, etc. ) from different providers.  This does not
 197  * mean that the client application isn't portable, it simply means that a
 198  * client has to use a runtime system provided by the same provider that was
 199  * used to compile the schema.
 200  *
 201  *
 202  * <h3>Discovery of JAXB implementation</h3>
 203  * <p>
 204  * When one of the <tt>newInstance</tt> methods is called, a JAXB implementation is discovered
 205  * by the following steps.
 206  *
 207  * <ol>
 208  *
 209  * <li>
 210  * For each package/class explicitly passed in to the {@link #newInstance} method, in the order they are specified,
 211  * <tt>jaxb.properties</tt> file is looked up in its package, by using the associated classloader &mdash;
 212  * this is {@link Class#getClassLoader() the owner class loader} for a {@link Class} argument, and for a package
 213  * the specified {@link ClassLoader}.
 214  *
 215  * <p>
 216  * If such a file is discovered, it is {@link Properties#load(InputStream) loaded} as a property file, and
 217  * the value of the {@link #JAXB_CONTEXT_FACTORY} key will be assumed to be the provider factory class.
 218  * This class is then loaded by the associated class loader discussed above.
 219  *
 220  * <p>
 221  * This phase of the look up allows some packages to force the use of a certain JAXB implementation.
 222  * (For example, perhaps the schema compiler has generated some vendor extension in the code.)
 223  *
 224  * <li>
 225  * If the system property {@link #JAXB_CONTEXT_FACTORY} exists, then its value is assumed to be the provider
 226  * factory class. This phase of the look up enables per-JVM override of the JAXB implementation.
 227  *
 228  * <li>
 229  * Provider of {@link javax.xml.bind.JAXBContextFactory} is loaded using the service-provider loading
 230  * facilities, defined by the {@link java.util.ServiceLoader} class, to attempt
 231  * to locate and load an implementation of the service using the {@linkplain
 232  * java.util.ServiceLoader#load(java.lang.Class) default loading mechanism}: the service-provider loading facility
 233  * will use the {@linkplain java.lang.Thread#getContextClassLoader() current thread's context class loader}
 234  * to attempt to load the context factory. If the context class loader is null, the
 235  * {@linkplain ClassLoader#getSystemClassLoader() system class loader} will be used.
 236  * <br>
 237  * In case of {@link java.util.ServiceConfigurationError service
 238  * configuration error} a {@link javax.xml.bind.JAXBException} will be thrown.
 239  * </li>
 240  *
 241  * <li>
 242  * Look for resource <tt>/META-INF/services/javax.xml.bind.JAXBContext</tt> using provided class loader.
 243  * Methods without class loader parameter use {@code Thread.currentThread().getContextClassLoader()}.
 244  * If such a resource exists, its content is assumed to be the provider factory class and must supply
 245  * an implementation class containing the following method signatures:
 246  *
 247  * <pre>
 248  *
 249  * public static JAXBContext createContext(
 250  *                                      String contextPath,
 251  *                                      ClassLoader classLoader,
 252  *                                      Map&lt;String,Object&gt; properties throws JAXBException
 253  *
 254  * public static JAXBContext createContext(
 255  *                                      Class[] classes,
 256  *                                      Map&lt;String,Object&gt; properties ) throws JAXBException
 257  * </pre>
 258  *
 259  * <li>
 260  * Look for resource <tt>/META-INF/services/javax.xml.bind.JAXBContext</tt> using provided class loader.
 261  * Methods without class loader parameter use {@code Thread.currentThread().getContextClassLoader()}.
 262  * If such a resource exists, its content is assumed to be the provider factory class and must supply
 263  * an implementation class containing the following method signatures:
 264  *
 265  * <pre>
 266  *
 267  * public static JAXBContext createContext(
 268  *                                      String contextPath,
 269  *                                      ClassLoader classLoader,
 270  *                                      Map&lt;String,Object&gt; properties throws JAXBException
 271  *
 272  * public static JAXBContext createContext(
 273  *                                      Class[] classes,
 274  *                                      Map&lt;String,Object&gt; properties ) throws JAXBException
 275  * </pre>
 276  * </li>
 277  *
 278  * <li>
 279  * Finally, if all the steps above fail, then the rest of the look up is unspecified. That said,
 280  * the recommended behavior is to simply look for some hard-coded platform default JAXB implementation.
 281  * This phase of the look up is so that JavaSE can have its own JAXB implementation as the last resort.
 282  * </ol>
 283  *
 284  * <p>
 285  * Once the provider factory class {@link javax.xml.bind.JAXBContextFactory} is discovered, one of its methods
 286  * {@link javax.xml.bind.JAXBContextFactory#createContext(String, ClassLoader, java.util.Map)} or
 287  * {@link javax.xml.bind.JAXBContextFactory#createContext(Class[], java.util.Map)} is invoked


 288  * to create a {@link JAXBContext}.
 289  *
 290  * <p/>
 291  *
 292  * @apiNote
 293  * <p>Service discovery method using file /META-INF/services/javax.xml.bind.JAXBContext (described in step 4)
 294  * and leveraging provider's static methods is supported only to allow backwards compatibility, but it is strongly
 295  * recommended to migrate to standard ServiceLoader mechanism (described in step 3).
 296  *
 297  * @implNote
 298  * Within the last step, if Glassfish AS environment detected, its specific service loader is used to find factory class.
 299  *
 300  * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li><li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li><li>Joe Fialli, Sun Microsystems, Inc.</li></ul>
 301  * @see Marshaller
 302  * @see Unmarshaller
 303  * @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>
 304  * @since 1.6, JAXB 1.0
 305  */
 306 public abstract class JAXBContext {
 307 
 308     /**
 309      * The name of the property that contains the name of the class capable
 310      * of creating new <tt>JAXBContext</tt> objects.
 311      */
 312     public static final String JAXB_CONTEXT_FACTORY = "javax.xml.bind.JAXBContextFactory";


 313 
 314     protected JAXBContext() {
 315     }
 316 
 317 
 318     /**
 319      * <p>
 320      * Create a new instance of a <tt>JAXBContext</tt> class.
 321      *
 322      * <p>
 323      * This is a convenience method to invoke the
 324      * {@link #newInstance(String,ClassLoader)} method with
 325      * the context class loader of the current thread.
 326      *
 327      * @throws JAXBException if an error was encountered while creating the
 328      *                       <tt>JAXBContext</tt> such as
 329      * <ol>
 330      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>
 331      *   <li>an ambiguity among global elements contained in the contextPath</li>
 332      *   <li>failure to locate a value for the context factory provider property</li>
 333      *   <li>mixing schema derived packages from different providers on the same contextPath</li>
 334      * </ol>
 335      */
 336     public static JAXBContext newInstance( String contextPath )
 337         throws JAXBException {
 338 
 339         //return newInstance( contextPath, JAXBContext.class.getClassLoader() );
 340         return newInstance( contextPath, getContextClassLoader());
 341     }
 342 
 343     /**
 344      * <p>
 345      * Create a new instance of a <tt>JAXBContext</tt> class.
 346      *
 347      * <p>
 348      * The client application must supply a context path which is a list of
 349      * colon (':', \u005Cu003A) separated java package names that contain
 350      * schema-derived classes and/or fully qualified JAXB-annotated classes.
 351      * Schema-derived
 352      * code is registered with the JAXBContext by the
 353      * ObjectFactory.class generated per package.
 354      * Alternatively than being listed in the context path, programmer
 355      * annotated JAXB mapped classes can be listed in a
 356      * <tt>jaxb.index</tt> resource file, format described below.
 357      * Note that a java package can contain both schema-derived classes and
 358      * user annotated JAXB classes. Additionally, the java package may
 359      * contain JAXB package annotations  that must be processed. (see JLS,
 360      * Section 7.4.1 "Named Packages").
 361      * </p>
 362      *
 363      * <p>
 364      * Every package listed on the contextPath must meet <b>one or both</b> of the
 365      * following conditions otherwise a <tt>JAXBException</tt> will be thrown:


 421      *      This class loader will be used to locate the implementation
 422      *      classes.
 423      *
 424      * @return a new instance of a <tt>JAXBContext</tt>
 425      * @throws JAXBException if an error was encountered while creating the
 426      *                       <tt>JAXBContext</tt> such as
 427      * <ol>
 428      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>
 429      *   <li>an ambiguity among global elements contained in the contextPath</li>
 430      *   <li>failure to locate a value for the context factory provider property</li>
 431      *   <li>mixing schema derived packages from different providers on the same contextPath</li>
 432      * </ol>
 433      */
 434     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader ) throws JAXBException {
 435 
 436         return newInstance(contextPath,classLoader,Collections.<String,Object>emptyMap());
 437     }
 438 
 439     /**
 440      * <p>
 441      * Create a new instance of a <tt>JAXBContext</tt> class.
 442      *
 443      * <p>
 444      * This is mostly the same as {@link JAXBContext#newInstance(String, ClassLoader)},
 445      * but this version allows you to pass in provider-specific properties to configure
 446      * the instantiation of {@link JAXBContext}.
 447      *
 448      * <p>
 449      * The interpretation of properties is up to implementations. Implementations should
 450      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.
 451      *
 452      * @param contextPath list of java package names that contain schema derived classes
 453      * @param classLoader
 454      *      This class loader will be used to locate the implementation classes.
 455      * @param properties
 456      *      provider-specific properties. Can be null, which means the same thing as passing
 457      *      in an empty map.
 458      *
 459      * @return a new instance of a <tt>JAXBContext</tt>
 460      * @throws JAXBException if an error was encountered while creating the
 461      *                       <tt>JAXBContext</tt> such as


 468      * @since 1.6, JAXB 2.0
 469      */
 470     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader, Map<String,?>  properties  )
 471         throws JAXBException {
 472 
 473         return ContextFinder.find(
 474                         /* The default property name according to the JAXB spec */
 475                         JAXB_CONTEXT_FACTORY,
 476 
 477                         /* the context path supplied by the client app */
 478                         contextPath,
 479 
 480                         /* class loader to be used */
 481                         classLoader,
 482                         properties );
 483     }
 484 
 485 // TODO: resurrect this once we introduce external annotations
 486 //    /**
 487 //     * <p>
 488 //     * Create a new instance of a <tt>JAXBContext</tt> class.
 489 //     *
 490 //     * <p>
 491 //     * The client application must supply a list of classes that the new
 492 //     * context object needs to recognize.
 493 //     *
 494 //     * Not only the new context will recognize all the classes specified,
 495 //     * but it will also recognize any classes that are directly/indirectly
 496 //     * referenced statically from the specified classes.
 497 //     *
 498 //     * For example, in the following Java code, if you do
 499 //     * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}
 500 //     * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt>:
 501 //     * <pre>
 502 //     * class Foo {
 503 //     *      Bar b;
 504 //     * }
 505 //     * class Bar { int x; }
 506 //     * class Zot extends Bar { int y; }
 507 //     * </pre>
 508 //     *
 509 //     * Therefore, a typical client application only needs to specify the
 510 //     * top-level classes, but it needs to be careful.
 511 //     *
 512 //     * TODO: if we are to define other mechanisms, refer to them.
 513 //     *
 514 //     * @param externalBindings
 515 //     *      list of external binding files. Can be null or empty if none is used.
 516 //     *      when specified, those files determine how the classes are bound.
 517 //     *
 518 //     * @param classesToBeBound
 519 //     *      list of java classes to be recognized by the new {@link JAXBContext}.
 520 //     *      Can be empty, in which case a {@link JAXBContext} that only knows about
 521 //     *      spec-defined classes will be returned.
 522 //     *
 523 //     * @return
 524 //     *      A new instance of a <tt>JAXBContext</tt>.
 525 //     *
 526 //     * @throws JAXBException
 527 //     *      if an error was encountered while creating the
 528 //     *      <tt>JAXBContext</tt>, such as (but not limited to):
 529 //     * <ol>
 530 //     *  <li>No JAXB implementation was discovered
 531 //     *  <li>Classes use JAXB annotations incorrectly
 532 //     *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 533 //     *  <li>Specified external bindings are incorrect
 534 //     *  <li>The JAXB implementation was unable to locate
 535 //     *      provider-specific out-of-band information (such as additional
 536 //     *      files generated at the development time.)
 537 //     * </ol>
 538 //     *
 539 //     * @throws IllegalArgumentException
 540 //     *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})
 541 //     *
 542 //     * @since JAXB 2.0
 543 //     */
 544 //    public static JAXBContext newInstance( Source[] externalBindings, Class... classesToBeBound )
 545 //        throws JAXBException {
 546 //
 547 //        // empty class list is not an error, because the context will still include
 548 //        // spec-specified classes like String and Integer.
 549 //        // if(classesToBeBound.length==0)
 550 //        //    throw new IllegalArgumentException();
 551 //
 552 //        // but it is an error to have nulls in it.
 553 //        for( int i=classesToBeBound.length-1; i>=0; i-- )
 554 //            if(classesToBeBound[i]==null)
 555 //                throw new IllegalArgumentException();
 556 //
 557 //        return ContextFinder.find(externalBindings,classesToBeBound);
 558 //    }
 559 
 560     /**
 561      * <p>
 562      * Create a new instance of a <tt>JAXBContext</tt> class.
 563      *
 564      * <p>
 565      * The client application must supply a list of classes that the new
 566      * context object needs to recognize.
 567      *
 568      * Not only the new context will recognize all the classes specified,
 569      * but it will also recognize any classes that are directly/indirectly
 570      * referenced statically from the specified classes. Subclasses of
 571      * referenced classes nor <tt>@XmlTransient</tt> referenced classes
 572      * are not registered with JAXBContext.
 573      *
 574      * For example, in the following Java code, if you do
 575      * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}
 576      * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt> or <tt>FooBar</tt>:
 577      * <pre>
 578      * class Foo {
 579      *      @XmlTransient FooBar c;
 580      *      Bar b;
 581      * }
 582      * class Bar { int x; }


 584      * class FooBar { }
 585      * </pre>
 586      *
 587      * Therefore, a typical client application only needs to specify the
 588      * top-level classes, but it needs to be careful.
 589      *
 590      * <p>
 591      * Note that for each java package registered with JAXBContext,
 592      * when the optional package annotations exist, they must be processed.
 593      * (see JLS, Section 7.4.1 "Named Packages").
 594      *
 595      * <p>
 596      * The steps involved in discovering the JAXB implementation is discussed in the class javadoc.
 597      *
 598      * @param classesToBeBound
 599      *      list of java classes to be recognized by the new {@link JAXBContext}.
 600      *      Can be empty, in which case a {@link JAXBContext} that only knows about
 601      *      spec-defined classes will be returned.
 602      *
 603      * @return
 604      *      A new instance of a <tt>JAXBContext</tt>.
 605      *
 606      * @throws JAXBException
 607      *      if an error was encountered while creating the
 608      *      <tt>JAXBContext</tt>, such as (but not limited to):
 609      * <ol>
 610      *  <li>No JAXB implementation was discovered
 611      *  <li>Classes use JAXB annotations incorrectly
 612      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 613      *  <li>The JAXB implementation was unable to locate
 614      *      provider-specific out-of-band information (such as additional
 615      *      files generated at the development time.)
 616      * </ol>
 617      *
 618      * @throws IllegalArgumentException
 619      *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})
 620      *
 621      * @since 1.6, JAXB 2.0
 622      */
 623     public static JAXBContext newInstance( Class<?> ... classesToBeBound )
 624         throws JAXBException {
 625 
 626         return newInstance(classesToBeBound,Collections.<String,Object>emptyMap());
 627     }
 628 
 629     /**
 630      * <p>
 631      * Create a new instance of a <tt>JAXBContext</tt> class.
 632      *
 633      * <p>
 634      * An overloading of {@link JAXBContext#newInstance(Class...)}
 635      * to configure 'properties' for this instantiation of {@link JAXBContext}.
 636      *
 637      * <p>
 638      * The interpretation of properties is up to implementations. Implementations should
 639      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.
 640      *
 641      * @param classesToBeBound
 642      *      list of java classes to be recognized by the new {@link JAXBContext}.
 643      *      Can be empty, in which case a {@link JAXBContext} that only knows about
 644      *      spec-defined classes will be returned.
 645      * @param properties
 646      *      provider-specific properties. Can be null, which means the same thing as passing
 647      *      in an empty map.
 648      *
 649      * @return
 650      *      A new instance of a <tt>JAXBContext</tt>.
 651      *
 652      * @throws JAXBException
 653      *      if an error was encountered while creating the
 654      *      <tt>JAXBContext</tt>, such as (but not limited to):
 655      * <ol>
 656      *  <li>No JAXB implementation was discovered
 657      *  <li>Classes use JAXB annotations incorrectly
 658      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)
 659      *  <li>The JAXB implementation was unable to locate
 660      *      provider-specific out-of-band information (such as additional
 661      *      files generated at the development time.)
 662      * </ol>
 663      *
 664      * @throws IllegalArgumentException
 665      *      if the parameter contains {@code null} (i.e., {@code newInstance(null,someMap);})
 666      *
 667      * @since 1.6, JAXB 2.0
 668      */
 669     public static JAXBContext newInstance( Class<?>[] classesToBeBound, Map<String,?> properties )
 670         throws JAXBException {
 671 
 672         if (classesToBeBound == null) {
 673                 throw new IllegalArgumentException();
 674         }
 675 
 676         // but it is an error to have nulls in it.
 677         for (int i = classesToBeBound.length - 1; i >= 0; i--) {
 678             if (classesToBeBound[i] == null) {
 679                 throw new IllegalArgumentException();
 680             }
 681         }
 682 
 683         return ContextFinder.find(classesToBeBound,properties);
 684     }
 685 
 686     /**
 687      * Create an <tt>Unmarshaller</tt> object that can be used to convert XML
 688      * data into a java content tree.
 689      *


 781      *
 782      * @throws IOException
 783      *      if {@link SchemaOutputResolver} throws an {@link IOException}.
 784      *
 785      * @throws UnsupportedOperationException
 786      *      Calling this method on JAXB 1.0 implementations will throw
 787      *      an UnsupportedOperationException.
 788      *
 789      * @since 1.6, JAXB 2.0
 790      */
 791     public void generateSchema(SchemaOutputResolver outputResolver) throws IOException  {
 792         // to make JAXB 1.0 implementations work, this method must not be
 793         // abstract
 794         throw new UnsupportedOperationException();
 795     }
 796 
 797     private static ClassLoader getContextClassLoader() {
 798         if (System.getSecurityManager() == null) {
 799             return Thread.currentThread().getContextClassLoader();
 800         } else {
 801             return java.security.AccessController.doPrivileged(
 802                     new java.security.PrivilegedAction<ClassLoader>() {
 803                         public ClassLoader run() {
 804                             return Thread.currentThread().getContextClassLoader();
 805                         }
 806                     });
 807         }
 808     }
 809 
 810 }
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