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 package javax.xml.bind;

 import org.w3c.dom.Node;

 import java.util.Collections;

 import java.util.Map;

 import java.util.Properties;

 import java.io.IOException;

 import java.io.InputStream;

 /**

  * <p>

  * The <tt>JAXBContext</tt> class provides the client's entry point to the

  * JAXB API. It provides an abstraction for managing the XML/Java binding

  * information necessary to implement the JAXB binding framework operations:

  * unmarshal, marshal and validate.

  *

  * <p>A client application normally obtains new instances of this class using

  * one of these two styles for newInstance methods, although there are other

  * specialized forms of the method available:

  *

  * <ul>

  *   <li>{@link #newInstance(String,ClassLoader) JAXBContext.newInstance( "com.acme.foo:com.acme.bar" )} <br/>

  *   The JAXBContext instance is initialized from a list of colon

  *   separated Java package names. Each java package contains

  *   JAXB mapped classes, schema-derived classes and/or user annotated

  *   classes. Additionally, the java package may contain JAXB package annotations

  *   that must be processed. (see JLS, Section 7.4.1 "Named Packages").

  *   </li>

  *   <li>{@link #newInstance(Class...) JAXBContext.newInstance( com.acme.foo.Foo.class )} <br/>

  *    The JAXBContext instance is initialized with class(es)

  *    passed as parameter(s) and classes that are statically reachable from

  *    these class(es). See {@link #newInstance(Class...)} for details.

  *   </li>

  * </ul>

  *

  * <p>

  * <i><B>SPEC REQUIREMENT:</B> the provider must supply an implementation

  * class containing the following method signatures:</i>

  *

  * <pre>

  * public static JAXBContext createContext( String contextPath, ClassLoader classLoader, Map<String,Object> properties ) throws JAXBException

  * public static JAXBContext createContext( Class[] classes, Map<String,Object> properties ) throws JAXBException

  * </pre>

  *

  * <p><i>

  * The following JAXB 1.0 requirement is only required for schema to

  * java interface/implementation binding. It does not apply to JAXB annotated

  * classes. JAXB Providers must generate a <tt>jaxb.properties</tt> file in

  * each package containing schema derived classes.  The property file must

  * contain a property named <tt>javax.xml.bind.context.factory</tt> whose

  * value is the name of the class that implements the <tt>createContext</tt>

  * APIs.</i>

  *

  * <p><i>

  * The class supplied by the provider does not have to be assignable to

  * <tt>javax.xml.bind.JAXBContext</tt>, it simply has to provide a class that

  * implements the <tt>createContext</tt> APIs.</i>

  *

  * <p><i>

  * In addition, the provider must call the

  * {@link DatatypeConverter#setDatatypeConverter(DatatypeConverterInterface)

  * DatatypeConverter.setDatatypeConverter} api prior to any client

  * invocations of the marshal and unmarshal methods.  This is necessary to

  * configure the datatype converter that will be used during these operations.</i>

  *

  * <a name="Unmarshalling"></a>

  * <h3>Unmarshalling</h3>

  * <p>

  * The {@link Unmarshaller} class provides the client application the ability

  * to convert XML data into a tree of Java content objects.

  * The unmarshal method allows for

  * any global XML element declared in the schema to be unmarshalled as

  * the root of an instance document.

  * Additionally, the unmarshal method allows for an unrecognized root element that

  * has  an xsi:type attribute's value that references a type definition declared in

  * the schema  to be unmarshalled as the root of an instance document.

  * The <tt>JAXBContext</tt> object

  * allows the merging of global elements and type definitions across a set of schemas (listed

  * in the <tt>contextPath</tt>). Since each schema in the schema set can belong

  * to distinct namespaces, the unification of schemas to an unmarshalling

  * context should be namespace independent.  This means that a client

  * application is able to unmarshal XML documents that are instances of

  * any of the schemas listed in the <tt>contextPath</tt>.  For example:

  *

  * <pre>

  *        JAXBContext jc = JAXBContext.newInstance( "com.acme.foo:com.acme.bar" );

  *        Unmarshaller u = jc.createUnmarshaller();

  *        FooObject fooObj = (FooObject)u.unmarshal( new File( "foo.xml" ) ); // ok

  *        BarObject barObj = (BarObject)u.unmarshal( new File( "bar.xml" ) ); // ok

  *        BazObject bazObj = (BazObject)u.unmarshal( new File( "baz.xml" ) ); // error, "com.acme.baz" not in contextPath

  * </pre>

  *

  * <p>

  * The client application may also generate Java content trees explicitly rather

  * than unmarshalling existing XML data.  For all JAXB-annotated value classes,

  * an application can create content using constructors.

  * For schema-derived interface/implementation classes and for the

  * creation of elements that are not bound to a JAXB-annotated

  * class, an application needs to have access and knowledge about each of

  * the schema derived <tt> ObjectFactory</tt> classes that exist in each of

  * java packages contained in the <tt>contextPath</tt>.  For each schema

  * derived java class, there is a static factory method that produces objects

  * of that type.  For example,

  * assume that after compiling a schema, you have a package <tt>com.acme.foo</tt>

  * that contains a schema derived interface named <tt>PurchaseOrder</tt>.  In

  * order to create objects of that type, the client application would use the

  * factory method like this:

  *

  * <pre>

  *       com.acme.foo.PurchaseOrder po =

  *           com.acme.foo.ObjectFactory.createPurchaseOrder();

  * </pre>

  *

  * <p>

  * Once the client application has an instance of the the schema derived object,

  * it can use the mutator methods to set content on it.

  *

  * <p>

  * For more information on the generated <tt>ObjectFactory</tt> classes, see

  * Section 4.2 <i>Java Package</i> of the specification.

  *

  * <p>

  * <i><B>SPEC REQUIREMENT:</B> the provider must generate a class in each

  * package that contains all of the necessary object factory methods for that

  * package named ObjectFactory as well as the static

  * <tt>newInstance( javaContentInterface )</tt> method</i>

  *

  * <h3>Marshalling</h3>

  * <p>

  * The {@link Marshaller} class provides the client application the ability

  * to convert a Java content tree back into XML data.  There is no difference

  * between marshalling a content tree that is created manually using the factory

  * methods and marshalling a content tree that is the result an <tt>unmarshal

  * </tt> operation.  Clients can marshal a java content tree back to XML data

  * to a <tt>java.io.OutputStream</tt> or a <tt>java.io.Writer</tt>.  The

  * marshalling process can alternatively produce SAX2 event streams to a

  * registered <tt>ContentHandler</tt> or produce a DOM Node object.

  * Client applications have control over the output encoding as well as

  * whether or not to marshal the XML data as a complete document or

  * as a fragment.

  *

  * <p>

  * Here is a simple example that unmarshals an XML document and then marshals

  * it back out:

  *

  * <pre>

  *        JAXBContext jc = JAXBContext.newInstance( "com.acme.foo" );

  *

  *        // unmarshal from foo.xml

  *        Unmarshaller u = jc.createUnmarshaller();

  *        FooObject fooObj = (FooObject)u.unmarshal( new File( "foo.xml" ) );

  *

  *        // marshal to System.out

  *        Marshaller m = jc.createMarshaller();

  *        m.marshal( fooObj, System.out );

  * </pre>

  *

  *

  * <h3>Validation</h3>

  * <p>

  * Validation has been changed significantly since JAXB 1.0.  The {@link Validator}

  * class has been deprecated and made optional.  This means that you are advised

  * not to use this class and, in fact, it may not even be available depending on

  * your JAXB provider.  JAXB 1.0 client applications that rely on <tt>Validator</tt>

  * will still work properly when deployed with the JAXB 1.0 runtime system.

  *

  * In JAXB 2.0, the {@link Unmarshaller} has included convenince methods that expose

  * the JAXP 1.3 {@link javax.xml.validation} framework.  Please refer to the

  * {@link Unmarshaller#setSchema(javax.xml.validation.Schema)} API for more

  * information.

  *

  *

  * <h3>JAXB Runtime Binding Framework Compatibility</h3>

  * <p>

  * The following JAXB 1.0 restriction only applies to binding schema to

  * interfaces/implementation classes.

  * Since this binding does not require a common runtime system, a JAXB

  * client application must not attempt to mix runtime objects (<tt>JAXBContext,

  * Marshaller</tt>, etc. ) from different providers.  This does not

  * mean that the client application isn't portable, it simply means that a

  * client has to use a runtime system provided by the same provider that was

  * used to compile the schema.

  *

  *

  * <h3>Discovery of JAXB implementation</h3>

  * <p>

  * When one of the <tt>newInstance</tt> methods is called, a JAXB implementation is discovered

  * by the following steps.

  *

  * <ol>

  * <li>

  * For each package/class explicitly passed in to the {@link #newInstance} method, in the order they are specified,

  * <tt>jaxb.properties</tt> file is looked up in its package, by using the associated classloader &mdash;

  * this is {@link Class#getClassLoader() the owner class loader} for a {@link Class} argument, and for a package

  * the specified {@link ClassLoader}.

  *

  * <p>

  * If such a file is discovered, it is {@link Properties#load(InputStream) loaded} as a property file, and

  * the value of the {@link #JAXB_CONTEXT_FACTORY} key will be assumed to be the provider factory class.

  * This class is then loaded by the associated classloader discussed above.

  *

  * <p>

  * This phase of the look up allows some packages to force the use of a certain JAXB implementation.

  * (For example, perhaps the schema compiler has generated some vendor extension in the code.)

  *

  * <li>

  * If the system property {@link #JAXB_CONTEXT_FACTORY} exists, then its value is assumed to be the provider

  * factory class. This phase of the look up enables per-JVM override of the JAXB implementation.

  *

  * <li>

  * Look for <tt>/META-INF/services/javax.xml.bind.JAXBContext</tt> file in the associated classloader.

  * This file follows the standard service descriptor convention, and if such a file exists, its content

  * is assumed to be the provider factory class. This phase of the look up is for automatic discovery.

  * It allows users to just put a JAXB implementation in a classpath and use it without any furhter configuration.

  *

  * <li>

  * Finally, if all the steps above fail, then the rest of the look up is unspecified. That said,

  * the recommended behavior is to simply look for some hard-coded platform default JAXB implementation.

  * This phase of the look up is so that JavaSE can have its own JAXB implementation as the last resort.

  * </ol>

  *

  * <p>

  * Once the provider factory class is discovered, its

  * <tt>public static JAXBContext createContext(String,ClassLoader,Map)</tt> method

  * (see {@link #newInstance(String, ClassLoader, Map)} for the parameter semantics.)

  * or <tt>public static JAXBContext createContet(Class[],Map)</tt> method

  * (see {@link #newInstance(Class[], Map)} for the parameter semantics) are invoked

  * to create a {@link JAXBContext}.

  *

  * @author <ul><li>Ryan Shoemaker, Sun Microsystems, Inc.</li><li>Kohsuke Kawaguchi, Sun Microsystems, Inc.</li><li>Joe Fialli, Sun Microsystems, Inc.</li></ul>

  * @see Marshaller

  * @see Unmarshaller

  * @see S 7.4.1 "Named Packages" in Java Language Specification</a>

  * @since JAXB1.0

  */

 public abstract class JAXBContext {

     /**

      * The name of the property that contains the name of the class capable

      * of creating new <tt>JAXBContext</tt> objects.

      */

     public static final String JAXB_CONTEXT_FACTORY =

         "javax.xml.bind.context.factory";

     protected JAXBContext() {

     }

     /**

      * <p>

      * Obtain a new instance of a <tt>JAXBContext</tt> class.

      *

      * <p>

      * This is a convenience method to invoke the

      * {@link #newInstance(String,ClassLoader)} method with

      * the context class loader of the current thread.

      *

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>JAXBContext</tt> such as

      * <ol>

      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>

      *   <li>an ambiguity among global elements contained in the contextPath</li>

      *   <li>failure to locate a value for the context factory provider property</li>

      *   <li>mixing schema derived packages from different providers on the same contextPath</li>

      * </ol>

      */

     public static JAXBContext newInstance( String contextPath )

         throws JAXBException {

         //return newInstance( contextPath, JAXBContext.class.getClassLoader() );

         return newInstance( contextPath, getContextClassLoader());

     }

     /**

      * <p>

      * Obtain a new instance of a <tt>JAXBContext</tt> class.

      *

      * <p>

      * The client application must supply a context path which is a list of

      * colon (':', \u005Cu003A) separated java package names that contain

      * schema-derived classes and/or fully qualified JAXB-annotated classes.

      * Schema-derived

      * code is registered with the JAXBContext by the

      * ObjectFactory.class generated per package.

      * Alternatively than being listed in the context path, programmer

      * annotated JAXB mapped classes can be listed in a

      * <tt>jaxb.index</tt> resource file, format described below.

      * Note that a java package can contain both schema-derived classes and

      * user annotated JAXB classes. Additionally, the java package may

      * contain JAXB package annotations  that must be processed. (see JLS,

      * Section 7.4.1 "Named Packages").

      * </p>

      *

      * <p>

      * Every package listed on the contextPath must meet <b>one or both</b> of the

      * following conditions otherwise a <tt>JAXBException</tt> will be thrown:

      * </p>

      * <ol>

      *   <li>it must contain ObjectFactory.class</li>

      *   <li>it must contain jaxb.index</li>

      * </ol>

      *

      * <p>

      * <b>Format for jaxb.index</b>

      * <p>

      * The file contains a newline-separated list of class names.

      * Space and tab characters, as well as blank

      * lines, are ignored. The comment character

      * is '#' (0x23); on each line all characters following the first comment

      * character are ignored. The file must be encoded in UTF-8. Classes that

      * are reachable, as defined in {@link #newInstance(Class...)}, from the

      * listed classes are also registered with JAXBContext.

      * <p>

      * Constraints on class name occuring in a <tt>jaxb.index</tt> file are:

      * <ul>

      *   <li>Must not end with ".class".</li>

      *   <li>Class names are resolved relative to package containing

      *       <tt>jaxb.index</tt> file. Only classes occuring directly in package

      *       containing <tt>jaxb.index</tt> file are allowed.</li>

      *   <li>Fully qualified class names are not allowed.

      *       A qualified class name,relative to current package,

      *       is only allowed to specify a nested or inner class.</li>

      * </ul>

      *

      * <p>

      * To maintain compatibility with JAXB 1.0 schema to java

      * interface/implementation binding, enabled by schema customization

      * <tt>&lt;jaxb:globalBindings valueClass="false"></tt>,

      * the JAXB provider will ensure that each package on the context path

      * has a <tt>jaxb.properties</tt> file which contains a value for the

      * <tt>javax.xml.bind.context.factory</tt> property and that all values

      * resolve to the same provider.  This requirement does not apply to

      * JAXB annotated classes.

      *

      * <p>

      * If there are any global XML element name collisions across the various

      * packages listed on the <tt>contextPath</tt>, a <tt>JAXBException</tt>

      * will be thrown.

      *

      * <p>

      * Mixing generated interface/impl bindings from multiple JAXB Providers

      * in the same context path may result in a <tt>JAXBException</tt>

      * being thrown.

      *

      * <p>

      * The steps involved in discovering the JAXB implementation is discussed in the class javadoc.

      *

      * @param contextPath list of java package names that contain schema

      *                    derived class and/or java to schema (JAXB-annotated)

      *                    mapped classes

      * @param classLoader

      *      This class loader will be used to locate the implementation

      *      classes.

      *

      * @return a new instance of a <tt>JAXBContext</tt>

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>JAXBContext</tt> such as

      * <ol>

      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>

      *   <li>an ambiguity among global elements contained in the contextPath</li>

      *   <li>failure to locate a value for the context factory provider property</li>

      *   <li>mixing schema derived packages from different providers on the same contextPath</li>

      * </ol>

      */

     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader ) throws JAXBException {

         return newInstance(contextPath,classLoader,Collections.<String,Object>emptyMap());

     }

     /**

      * <p>

      * Obtain a new instance of a <tt>JAXBContext</tt> class.

      *

      * <p>

      * This is mostly the same as {@link JAXBContext#newInstance(String, ClassLoader)},

      * but this version allows you to pass in provider-specific properties to configure

      * the instantiation of {@link JAXBContext}.

      *

      * <p>

      * The interpretation of properties is up to implementations. Implementations should

      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.

      *

      * @param contextPath list of java package names that contain schema derived classes

      * @param classLoader

      *      This class loader will be used to locate the implementation classes.

      * @param properties

      *      provider-specific properties. Can be null, which means the same thing as passing

      *      in an empty map.

      *

      * @return a new instance of a <tt>JAXBContext</tt>

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>JAXBContext</tt> such as

      * <ol>

      *   <li>failure to locate either ObjectFactory.class or jaxb.index in the packages</li>

      *   <li>an ambiguity among global elements contained in the contextPath</li>

      *   <li>failure to locate a value for the context factory provider property</li>

      *   <li>mixing schema derived packages from different providers on the same contextPath</li>

      * </ol>

      * @since JAXB2.0

      */

     public static JAXBContext newInstance( String contextPath, ClassLoader classLoader, Map<String,?>  properties  )

         throws JAXBException {

         return ContextFinder.find(

                         /* The default property name according to the JAXB spec */

                         JAXB_CONTEXT_FACTORY,

                         /* the context path supplied by the client app */

                         contextPath,

                         /* class loader to be used */

                         classLoader,

                         properties );

     }

 // TODO: resurrect this once we introduce external annotations

 //    /**

 //     * <p>

 //     * Obtain a new instance of a <tt>JAXBContext</tt> class.

 //     *

 //     * <p>

 //     * The client application must supply a list of classes that the new

 //     * context object needs to recognize.

 //     *

 //     * Not only the new context will recognize all the classes specified,

 //     * but it will also recognize any classes that are directly/indirectly

 //     * referenced statically from the specified classes.

 //     *

 //     * For example, in the following Java code, if you do

 //     * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}

 //     * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt>:

 //     * <pre>

 //     * class Foo {

 //     *      Bar b;

 //     * }

 //     * class Bar { int x; }

 //     * class Zot extends Bar { int y; }

 //     * </pre>

 //     *

 //     * Therefore, a typical client application only needs to specify the

 //     * top-level classes, but it needs to be careful.

 //     *

 //     * TODO: if we are to define other mechanisms, refer to them.

 //     *

 //     * @param externalBindings

 //     *      list of external binding files. Can be null or empty if none is used.

 //     *      when specified, those files determine how the classes are bound.

 //     *

 //     * @param classesToBeBound

 //     *      list of java classes to be recognized by the new {@link JAXBContext}.

 //     *      Can be empty, in which case a {@link JAXBContext} that only knows about

 //     *      spec-defined classes will be returned.

 //     *

 //     * @return

 //     *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.

 //     *

 //     * @throws JAXBException

 //     *      if an error was encountered while creating the

 //     *      <tt>JAXBContext</tt>, such as (but not limited to):

 //     * <ol>

 //     *  <li>No JAXB implementation was discovered

 //     *  <li>Classes use JAXB annotations incorrectly

 //     *  <li>Classes have colliding annotations (i.e., two classes with the same type name)

 //     *  <li>Specified external bindings are incorrect

 //     *  <li>The JAXB implementation was unable to locate

 //     *      provider-specific out-of-band information (such as additional

 //     *      files generated at the development time.)

 //     * </ol>

 //     *

 //     * @throws IllegalArgumentException

 //     *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})

 //     *

 //     * @since JAXB2.0

 //     */

 //    public static JAXBContext newInstance( Source[] externalBindings, Class... classesToBeBound )

 //        throws JAXBException {

 //

 //        // empty class list is not an error, because the context will still include

 //        // spec-specified classes like String and Integer.

 //        // if(classesToBeBound.length==0)

 //        //    throw new IllegalArgumentException();

 //

 //        // but it is an error to have nulls in it.

 //        for( int i=classesToBeBound.length-1; i>=0; i-- )

 //            if(classesToBeBound[i]==null)

 //                throw new IllegalArgumentException();

 //

 //        return ContextFinder.find(externalBindings,classesToBeBound);

 //    }

     /**

      * <p>

      * Obtain a new instance of a <tt>JAXBContext</tt> class.

      *

      * <p>

      * The client application must supply a list of classes that the new

      * context object needs to recognize.

      *

      * Not only the new context will recognize all the classes specified,

      * but it will also recognize any classes that are directly/indirectly

      * referenced statically from the specified classes. Subclasses of

      * referenced classes nor <tt>&#64;XmlTransient</tt> referenced classes

      * are not registered with JAXBContext.

      *

      * For example, in the following Java code, if you do

      * <tt>newInstance(Foo.class)</tt>, the newly created {@link JAXBContext}

      * will recognize both <tt>Foo</tt> and <tt>Bar</tt>, but not <tt>Zot</tt> or <tt>FooBar</tt>:

      * <pre>

      * class Foo {

      *      @XmlTransient FooBar c;

      *      Bar b;

      * }

      * class Bar { int x; }

      * class Zot extends Bar { int y; }

      * class FooBar { }

      * </pre>

      *

      * Therefore, a typical client application only needs to specify the

      * top-level classes, but it needs to be careful.

      *

      * <p>

      * Note that for each java package registered with JAXBContext,

      * when the optional package annotations exist, they must be processed.

      * (see JLS, Section 7.4.1 "Named Packages").

      *

      * <p>

      * The steps involved in discovering the JAXB implementation is discussed in the class javadoc.

      *

      * @param classesToBeBound

      *      list of java classes to be recognized by the new {@link JAXBContext}.

      *      Can be empty, in which case a {@link JAXBContext} that only knows about

      *      spec-defined classes will be returned.

      *

      * @return

      *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.

      *

      * @throws JAXBException

      *      if an error was encountered while creating the

      *      <tt>JAXBContext</tt>, such as (but not limited to):

      * <ol>

      *  <li>No JAXB implementation was discovered

      *  <li>Classes use JAXB annotations incorrectly

      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)

      *  <li>The JAXB implementation was unable to locate

      *      provider-specific out-of-band information (such as additional

      *      files generated at the development time.)

      * </ol>

      *

      * @throws IllegalArgumentException

      *      if the parameter contains {@code null} (i.e., {@code newInstance(null);})

      *

      * @since JAXB2.0

      */

     public static JAXBContext newInstance( Class... classesToBeBound )

         throws JAXBException {

         return newInstance(classesToBeBound,Collections.<String,Object>emptyMap());

     }

     /**

      * <p>

      * Obtain a new instance of a <tt>JAXBContext</tt> class.

      *

      * <p>

      * An overloading of {@link JAXBContext#newInstance(Class...)}

      * to configure 'properties' for this instantiation of {@link JAXBContext}.

      *

      * <p>

      * The interpretation of properties is up to implementations. Implementations should

      * throw <tt>JAXBException</tt> if it finds properties that it doesn't understand.

      *

      * @param classesToBeBound

      *      list of java classes to be recognized by the new {@link JAXBContext}.

      *      Can be empty, in which case a {@link JAXBContext} that only knows about

      *      spec-defined classes will be returned.

      * @param properties

      *      provider-specific properties. Can be null, which means the same thing as passing

      *      in an empty map.

      *

      * @return

      *      A new instance of a <tt>JAXBContext</tt>. Always non-null valid object.

      *

      * @throws JAXBException

      *      if an error was encountered while creating the

      *      <tt>JAXBContext</tt>, such as (but not limited to):

      * <ol>

      *  <li>No JAXB implementation was discovered

      *  <li>Classes use JAXB annotations incorrectly

      *  <li>Classes have colliding annotations (i.e., two classes with the same type name)

      *  <li>The JAXB implementation was unable to locate

      *      provider-specific out-of-band information (such as additional

      *      files generated at the development time.)

      * </ol>

      *

      * @throws IllegalArgumentException

      *      if the parameter contains {@code null} (i.e., {@code newInstance(null,someMap);})

      *

      * @since JAXB2.0

      */

     public static JAXBContext newInstance( Class[] classesToBeBound, Map<String,?> properties )

         throws JAXBException {

         if (classesToBeBound == null) {

                 throw new IllegalArgumentException();

         }

         // but it is an error to have nulls in it.

         for (int i = classesToBeBound.length - 1; i >= 0; i--) {

             if (classesToBeBound[i] == null) {

                 throw new IllegalArgumentException();

             }

         }

         return ContextFinder.find(classesToBeBound,properties);

     }

     /**

      * Create an <tt>Unmarshaller</tt> object that can be used to convert XML

      * data into a java content tree.

      *

      * @return an <tt>Unmarshaller</tt> object

      *

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>Unmarshaller</tt> object

      */

     public abstract Unmarshaller createUnmarshaller() throws JAXBException;

     /**

      * Create a <tt>Marshaller</tt> object that can be used to convert a

      * java content tree into XML data.

      *

      * @return a <tt>Marshaller</tt> object

      *

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>Marshaller</tt> object

      */

     public abstract Marshaller createMarshaller() throws JAXBException;

     /**

      * {@link Validator} has been made optional and deprecated in JAXB 2.0.  Please

      * refer to the javadoc for {@link Validator} for more detail.

      * <p>

      * Create a <tt>Validator</tt> object that can be used to validate a

      * java content tree against its source schema.

      *

      * @return a <tt>Validator</tt> object

      *

      * @throws JAXBException if an error was encountered while creating the

      *                       <tt>Validator</tt> object

      * @deprecated since JAXB2.0

      */

     public abstract Validator createValidator() throws JAXBException;

     /**

      * Creates a <tt>Binder</tt> object that can be used for

      * associative/in-place unmarshalling/marshalling.

      *

      * @param domType select the DOM API to use by passing in its DOM Node class.

      *

      * @return always a new valid <tt>Binder</tt> object.

      *

      * @throws UnsupportedOperationException

      *      if DOM API corresponding to <tt>domType</tt> is not supported by

      *      the implementation.

      *

      * @since JAXB2.0

      */

     public <T> Binder<T> createBinder(Class<T> domType) {

         // to make JAXB 1.0 implementations work, this method must not be

         // abstract

         throw new UnsupportedOperationException();

     }

     /**

      * Creates a <tt>Binder</tt> for W3C DOM.

      *

      * @return always a new valid <tt>Binder</tt> object.

      *

      * @since JAXB2.0

      */

     public Binder<Node> createBinder() {

         return createBinder(Node.class);

     }

     /**

      * Creates a <tt>JAXBIntrospector</tt> object that can be used to

      * introspect JAXB objects.

      *

      * @return

      *      always return a non-null valid <tt>JAXBIntrospector</tt> object.

      *

      * @throws UnsupportedOperationException

      *      Calling this method on JAXB 1.0 implementations will throw

      *      an UnsupportedOperationException.

      *

      * @since JAXB2.0

      */

     public JAXBIntrospector createJAXBIntrospector() {

         // to make JAXB 1.0 implementations work, this method must not be

         // abstract

         throw new UnsupportedOperationException();

     }

     /**

      * Generates the schema documents for this context.

      *

      * @param outputResolver

      *      this object controls the output to which schemas

      *      will be sent.

      *

      * @throws IOException

      *      if {@link SchemaOutputResolver} throws an {@link IOException}.

      *

      * @throws UnsupportedOperationException

      *      Calling this method on JAXB 1.0 implementations will throw

      *      an UnsupportedOperationException.

      *

      * @since JAXB 2.0

      */

     public void generateSchema(SchemaOutputResolver outputResolver) throws IOException  {

         // to make JAXB 1.0 implementations work, this method must not be

         // abstract

         throw new UnsupportedOperationException();

     }

     private static ClassLoader getContextClassLoader() {

         if (System.getSecurityManager() == null) {

             return Thread.currentThread().getContextClassLoader();

         } else {

             return (ClassLoader) java.security.AccessController.doPrivileged(

                     new java.security.PrivilegedAction() {

                         public java.lang.Object run() {

                             return Thread.currentThread().getContextClassLoader();

                         }

                     });

         }

     }

 }