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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>
67   * public static JAXBContext createContext( String contextPath, ClassLoader classLoader, Map&lt;String,Object> properties ) throws JAXBException
68   * public static JAXBContext createContext( Class[] classes, Map&lt;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 S 7.4.1 "Named Packages" in Java Language Specification</a>
260  * @since JAXB1.0
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>&lt;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 JAXB2.0
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 JAXB2.0
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>&#64;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      *      &#64;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 JAXB2.0
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 JAXB2.0
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 JAXB2.0
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 JAXB2.0
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 JAXB2.0
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 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 }