/*

  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package java.lang;

 import java.io.InputStream;

 import java.lang.annotation.Annotation;

 /**

  * Instances of the class {@code Class} represent classes and

  * interfaces in a running Java application.  An enum is a kind of

  * class and an annotation is a kind of interface.  Every array also

  * belongs to a class that is reflected as a {@code Class} object

  * that is shared by all arrays with the same element type and number

  * of dimensions.  The primitive Java types ({@code boolean},

  * {@code byte}, {@code char}, {@code short},

  * {@code int}, {@code long}, {@code float}, and

  * {@code double}), and the keyword {@code void} are also

  * represented as {@code Class} objects.

  *

  * <p> {@code Class} has no public constructor. Instead {@code Class}

  * objects are constructed automatically by the Java Virtual Machine as classes

  * are loaded and by calls to the {@code defineClass} method in the class

  * loader.

  *

  * <p> The following example uses a {@code Class} object to print the

  * class name of an object:

  *

  * <p> <blockquote><pre>

  *     void printClassName(Object obj) {

  *         System.out.println("The class of " + obj +

  *                            " is " + obj.getClass().getName());

  *     }

  * </pre></blockquote>

  *

  * <p> It is also possible to get the {@code Class} object for a named

  * type (or for void) using a class literal.  See Section 15.8.2 of

  * <cite>The Java&trade; Language Specification</cite>.

  * For example:

  *

  * <p> <blockquote>

  *     {@code System.out.println("The name of class Foo is: "+Foo.class.getName());}

  * </blockquote>

  *

  * @param <T> the type of the class modeled by this {@code Class}

  * object.  For example, the type of {@code String.class} is {@code

  * Class<String>}.  Use {@code Class<?>} if the class being modeled is

  * unknown.

  *

  * @author  unascribed

  * @see     java.lang.ClassLoader#defineClass(byte[], int, int)

  * @since   JDK1.0

  */

 public final

     class Class<T> implements java.io.Serializable {

 //                              java.lang.reflect.GenericDeclaration,

 //                              java.lang.reflect.Type,

 //                              java.lang.reflect.AnnotatedElement {

     private static final int ANNOTATION= 0x00002000;

     private static final int ENUM      = 0x00004000;

     private static final int SYNTHETIC = 0x00001000;

     /*

      * Constructor. Only the Java Virtual Machine creates Class

      * objects.

      */

     private Class() {}

     /**

      * Converts the object to a string. The string representation is the

      * string "class" or "interface", followed by a space, and then by the

      * fully qualified name of the class in the format returned by

      * {@code getName}.  If this {@code Class} object represents a

      * primitive type, this method returns the name of the primitive type.  If

      * this {@code Class} object represents void this method returns

      * "void".

      *

      * @return a string representation of this class object.

      */

     public String toString() {

         return (isInterface() ? "interface " : (isPrimitive() ? "" : "class "))

             + getName();

     }

     /**

      * Returns the {@code Class} object associated with the class or

      * interface with the given string name.  Invoking this method is

      * equivalent to:

      *

      * <blockquote>

      *  {@code Class.forName(className, true, currentLoader)}

      * </blockquote>

      *

      * where {@code currentLoader} denotes the defining class loader of

      * the current class.

      *

      * <p> For example, the following code fragment returns the

      * runtime {@code Class} descriptor for the class named

      * {@code java.lang.Thread}:

      *

      * <blockquote>

      *   {@code Class t = Class.forName("java.lang.Thread")}

      * </blockquote>

      * <p>

      * A call to {@code forName("X")} causes the class named

      * {@code X} to be initialized.

      *

      * @param      className   the fully qualified name of the desired class.

      * @return     the {@code Class} object for the class with the

      *             specified name.

      * @exception LinkageError if the linkage fails

      * @exception ExceptionInInitializerError if the initialization provoked

      *            by this method fails

      * @exception ClassNotFoundException if the class cannot be located

      */

     public static Class<?> forName(String className)

                 throws ClassNotFoundException {

         throw new UnsupportedOperationException();

     }

     /**

      * Creates a new instance of the class represented by this {@code Class}

      * object.  The class is instantiated as if by a {@code new}

      * expression with an empty argument list.  The class is initialized if it

      * has not already been initialized.

      *

      * <p>Note that this method propagates any exception thrown by the

      * nullary constructor, including a checked exception.  Use of

      * this method effectively bypasses the compile-time exception

      * checking that would otherwise be performed by the compiler.

      * The {@link

      * java.lang.reflect.Constructor#newInstance(java.lang.Object...)

      * Constructor.newInstance} method avoids this problem by wrapping

      * any exception thrown by the constructor in a (checked) {@link

      * java.lang.reflect.InvocationTargetException}.

      *

      * @return     a newly allocated instance of the class represented by this

      *             object.

      * @exception  IllegalAccessException  if the class or its nullary

      *               constructor is not accessible.

      * @exception  InstantiationException

      *               if this {@code Class} represents an abstract class,

      *               an interface, an array class, a primitive type, or void;

      *               or if the class has no nullary constructor;

      *               or if the instantiation fails for some other reason.

      * @exception  ExceptionInInitializerError if the initialization

      *               provoked by this method fails.

      * @exception  SecurityException

      *             If a security manager, <i>s</i>, is present and any of the

      *             following conditions is met:

      *

      *             <ul>

      *

      *             <li> invocation of

      *             {@link SecurityManager#checkMemberAccess

      *             s.checkMemberAccess(this, Member.PUBLIC)} denies

      *             creation of new instances of this class

      *

      *             <li> the caller's class loader is not the same as or an

      *             ancestor of the class loader for the current class and

      *             invocation of {@link SecurityManager#checkPackageAccess

      *             s.checkPackageAccess()} denies access to the package

      *             of this class

      *

      *             </ul>

      *

      */

     public T newInstance()

         throws InstantiationException, IllegalAccessException

     {

         throw new UnsupportedOperationException("Should be somehow supported");

     }

     /**

      * Determines if the specified {@code Object} is assignment-compatible

      * with the object represented by this {@code Class}.  This method is

      * the dynamic equivalent of the Java language {@code instanceof}

      * operator. The method returns {@code true} if the specified

      * {@code Object} argument is non-null and can be cast to the

      * reference type represented by this {@code Class} object without

      * raising a {@code ClassCastException.} It returns {@code false}

      * otherwise.

      *

      * <p> Specifically, if this {@code Class} object represents a

      * declared class, this method returns {@code true} if the specified

      * {@code Object} argument is an instance of the represented class (or

      * of any of its subclasses); it returns {@code false} otherwise. If

      * this {@code Class} object represents an array class, this method

      * returns {@code true} if the specified {@code Object} argument

      * can be converted to an object of the array class by an identity

      * conversion or by a widening reference conversion; it returns

      * {@code false} otherwise. If this {@code Class} object

      * represents an interface, this method returns {@code true} if the

      * class or any superclass of the specified {@code Object} argument

      * implements this interface; it returns {@code false} otherwise. If

      * this {@code Class} object represents a primitive type, this method

      * returns {@code false}.

      *

      * @param   obj the object to check

      * @return  true if {@code obj} is an instance of this class

      *

      * @since JDK1.1

      */

     public native boolean isInstance(Object obj);

     /**

      * Determines if the class or interface represented by this

      * {@code Class} object is either the same as, or is a superclass or

      * superinterface of, the class or interface represented by the specified

      * {@code Class} parameter. It returns {@code true} if so;

      * otherwise it returns {@code false}. If this {@code Class}

      * object represents a primitive type, this method returns

      * {@code true} if the specified {@code Class} parameter is

      * exactly this {@code Class} object; otherwise it returns

      * {@code false}.

      *

      * <p> Specifically, this method tests whether the type represented by the

      * specified {@code Class} parameter can be converted to the type

      * represented by this {@code Class} object via an identity conversion

      * or via a widening reference conversion. See <em>The Java Language

      * Specification</em>, sections 5.1.1 and 5.1.4 , for details.

      *

      * @param cls the {@code Class} object to be checked

      * @return the {@code boolean} value indicating whether objects of the

      * type {@code cls} can be assigned to objects of this class

      * @exception NullPointerException if the specified Class parameter is

      *            null.

      * @since JDK1.1

      */

     public native boolean isAssignableFrom(Class<?> cls);

     /**

      * Determines if the specified {@code Class} object represents an

      * interface type.

      *

      * @return  {@code true} if this object represents an interface;

      *          {@code false} otherwise.

      */

     public native boolean isInterface();

     /**

      * Determines if this {@code Class} object represents an array class.

      *

      * @return  {@code true} if this object represents an array class;

      *          {@code false} otherwise.

      * @since   JDK1.1

      */

     public native boolean isArray();

     /**

      * Determines if the specified {@code Class} object represents a

      * primitive type.

      *

      * <p> There are nine predefined {@code Class} objects to represent

      * the eight primitive types and void.  These are created by the Java

      * Virtual Machine, and have the same names as the primitive types that

      * they represent, namely {@code boolean}, {@code byte},

      * {@code char}, {@code short}, {@code int},

      * {@code long}, {@code float}, and {@code double}.

      *

      * <p> These objects may only be accessed via the following public static

      * final variables, and are the only {@code Class} objects for which

      * this method returns {@code true}.

      *

      * @return true if and only if this class represents a primitive type

      *

      * @see     java.lang.Boolean#TYPE

      * @see     java.lang.Character#TYPE

      * @see     java.lang.Byte#TYPE

      * @see     java.lang.Short#TYPE

      * @see     java.lang.Integer#TYPE

      * @see     java.lang.Long#TYPE

      * @see     java.lang.Float#TYPE

      * @see     java.lang.Double#TYPE

      * @see     java.lang.Void#TYPE

      * @since JDK1.1

      */

     public native boolean isPrimitive();

     /**

      * Returns true if this {@code Class} object represents an annotation

      * type.  Note that if this method returns true, {@link #isInterface()}

      * would also return true, as all annotation types are also interfaces.

      *

      * @return {@code true} if this class object represents an annotation

      *      type; {@code false} otherwise

      * @since 1.5

      */

     public boolean isAnnotation() {

         return (getModifiers() & ANNOTATION) != 0;

     }

     /**

      * Returns {@code true} if this class is a synthetic class;

      * returns {@code false} otherwise.

      * @return {@code true} if and only if this class is a synthetic class as

      *         defined by the Java Language Specification.

      * @since 1.5

      */

     public boolean isSynthetic() {

         return (getModifiers() & SYNTHETIC) != 0;

     }

     /**

      * Returns the  name of the entity (class, interface, array class,

      * primitive type, or void) represented by this {@code Class} object,

      * as a {@code String}.

      *

      * <p> If this class object represents a reference type that is not an

      * array type then the binary name of the class is returned, as specified

      * by

      * <cite>The Java&trade; Language Specification</cite>.

      *

      * <p> If this class object represents a primitive type or void, then the

      * name returned is a {@code String} equal to the Java language

      * keyword corresponding to the primitive type or void.

      *

      * <p> If this class object represents a class of arrays, then the internal

      * form of the name consists of the name of the element type preceded by

      * one or more '{@code [}' characters representing the depth of the array

      * nesting.  The encoding of element type names is as follows:

      *

      * <blockquote><table summary="Element types and encodings">

      * <tr><th> Element Type <th> &nbsp;&nbsp;&nbsp; <th> Encoding

      * <tr><td> boolean      <td> &nbsp;&nbsp;&nbsp; <td align=center> Z

      * <tr><td> byte         <td> &nbsp;&nbsp;&nbsp; <td align=center> B

      * <tr><td> char         <td> &nbsp;&nbsp;&nbsp; <td align=center> C

      * <tr><td> class or interface

      *                       <td> &nbsp;&nbsp;&nbsp; <td align=center> L<i>classname</i>;

      * <tr><td> double       <td> &nbsp;&nbsp;&nbsp; <td align=center> D

      * <tr><td> float        <td> &nbsp;&nbsp;&nbsp; <td align=center> F

      * <tr><td> int          <td> &nbsp;&nbsp;&nbsp; <td align=center> I

      * <tr><td> long         <td> &nbsp;&nbsp;&nbsp; <td align=center> J

      * <tr><td> short        <td> &nbsp;&nbsp;&nbsp; <td align=center> S

      * </table></blockquote>

      *

      * <p> The class or interface name <i>classname</i> is the binary name of

      * the class specified above.

      *

      * <p> Examples:

      * <blockquote><pre>

      * String.class.getName()

      *     returns "java.lang.String"

      * byte.class.getName()

      *     returns "byte"

      * (new Object[3]).getClass().getName()

      *     returns "[Ljava.lang.Object;"

      * (new int[3][4][5][6][7][8][9]).getClass().getName()

      *     returns "[[[[[[[I"

      * </pre></blockquote>

      *

      * @return  the name of the class or interface

      *          represented by this object.

      */

     public String getName() {

         throw new UnsupportedOperationException();

 //        String name = this.name;

 //        if (name == null)

 //            this.name = name = getName0();

 //        return name;

     }

     /**

      * Returns the {@code Class} representing the superclass of the entity

      * (class, interface, primitive type or void) represented by this

      * {@code Class}.  If this {@code Class} represents either the

      * {@code Object} class, an interface, a primitive type, or void, then

      * null is returned.  If this object represents an array class then the

      * {@code Class} object representing the {@code Object} class is

      * returned.

      *

      * @return the superclass of the class represented by this object.

      */

     public native Class<? super T> getSuperclass();

     /**

      * Returns the Java language modifiers for this class or interface, encoded

      * in an integer. The modifiers consist of the Java Virtual Machine's

      * constants for {@code public}, {@code protected},

      * {@code private}, {@code final}, {@code static},

      * {@code abstract} and {@code interface}; they should be decoded

      * using the methods of class {@code Modifier}.

      *

      * <p> If the underlying class is an array class, then its

      * {@code public}, {@code private} and {@code protected}

      * modifiers are the same as those of its component type.  If this

      * {@code Class} represents a primitive type or void, its

      * {@code public} modifier is always {@code true}, and its

      * {@code protected} and {@code private} modifiers are always

      * {@code false}. If this object represents an array class, a

      * primitive type or void, then its {@code final} modifier is always

      * {@code true} and its interface modifier is always

      * {@code false}. The values of its other modifiers are not determined

      * by this specification.

      *

      * <p> The modifier encodings are defined in <em>The Java Virtual Machine

      * Specification</em>, table 4.1.

      *

      * @return the {@code int} representing the modifiers for this class

      * @see     java.lang.reflect.Modifier

      * @since JDK1.1

      */

     public native int getModifiers();

     /**

      * Returns the simple name of the underlying class as given in the

      * source code. Returns an empty string if the underlying class is

      * anonymous.

      *

      * <p>The simple name of an array is the simple name of the

      * component type with "[]" appended.  In particular the simple

      * name of an array whose component type is anonymous is "[]".

      *

      * @return the simple name of the underlying class

      * @since 1.5

      */

     public String getSimpleName() {

         throw new UnsupportedOperationException();

 ////        if (isArray())

 ////            return getComponentType().getSimpleName()+"[]";

 ////

 ////        String simpleName = getSimpleBinaryName();

 ////        if (simpleName == null) { // top level class

 ////            simpleName = getName();

 ////            return simpleName.substring(simpleName.lastIndexOf(".")+1); // strip the package name

 ////        }

 ////        // According to JLS3 "Binary Compatibility" (13.1) the binary

 ////        // name of non-package classes (not top level) is the binary

 ////        // name of the immediately enclosing class followed by a '$' followed by:

 ////        // (for nested and inner classes): the simple name.

 ////        // (for local classes): 1 or more digits followed by the simple name.

 ////        // (for anonymous classes): 1 or more digits.

 ////

 ////        // Since getSimpleBinaryName() will strip the binary name of

 ////        // the immediatly enclosing class, we are now looking at a

 ////        // string that matches the regular expression "\$[0-9]*"

 ////        // followed by a simple name (considering the simple of an

 ////        // anonymous class to be the empty string).

 ////

 ////        // Remove leading "\$[0-9]*" from the name

 ////        int length = simpleName.length();

 ////        if (length < 1 || simpleName.charAt(0) != '$')

 ////            throw new InternalError("Malformed class name");

 ////        int index = 1;

 ////        while (index < length && isAsciiDigit(simpleName.charAt(index)))

 ////            index++;

 ////        // Eventually, this is the empty string iff this is an anonymous class

 ////        return simpleName.substring(index);

     }

     /**

      * Character.isDigit answers {@code true} to some non-ascii

      * digits.  This one does not.

      */

     private static boolean isAsciiDigit(char c) {

         return '0' <= c && c <= '9';

     }

     /**

      * Returns the canonical name of the underlying class as

      * defined by the Java Language Specification.  Returns null if

      * the underlying class does not have a canonical name (i.e., if

      * it is a local or anonymous class or an array whose component

      * type does not have a canonical name).

      * @return the canonical name of the underlying class if it exists, and

      * {@code null} otherwise.

      * @since 1.5

      */

     public String getCanonicalName() {

         throw new UnsupportedOperationException();

 //        if (isArray()) {

 //            String canonicalName = getComponentType().getCanonicalName();

 //            if (canonicalName != null)

 //                return canonicalName + "[]";

 //            else

 //                return null;

 //        }

 //        if (isLocalOrAnonymousClass())

 //            return null;

 //        Class<?> enclosingClass = getEnclosingClass();

 //        if (enclosingClass == null) { // top level class

 //            return getName();

 //        } else {

 //            String enclosingName = enclosingClass.getCanonicalName();

 //            if (enclosingName == null)

 //                return null;

 //            return enclosingName + "." + getSimpleName();

 //        }

     }

     /**

      * Finds a resource with a given name.  The rules for searching resources

      * associated with a given class are implemented by the defining

      * {@linkplain ClassLoader class loader} of the class.  This method

      * delegates to this object's class loader.  If this object was loaded by

      * the bootstrap class loader, the method delegates to {@link

      * ClassLoader#getSystemResourceAsStream}.

      *

      * <p> Before delegation, an absolute resource name is constructed from the

      * given resource name using this algorithm:

      *

      * <ul>

      *

      * <li> If the {@code name} begins with a {@code '/'}

      * (<tt>'&#92;u002f'</tt>), then the absolute name of the resource is the

      * portion of the {@code name} following the {@code '/'}.

      *

      * <li> Otherwise, the absolute name is of the following form:

      *

      * <blockquote>

      *   {@code modified_package_name/name}

      * </blockquote>

      *

      * <p> Where the {@code modified_package_name} is the package name of this

      * object with {@code '/'} substituted for {@code '.'}

      * (<tt>'&#92;u002e'</tt>).

      *

      * </ul>

      *

      * @param  name name of the desired resource

      * @return      A {@link java.io.InputStream} object or {@code null} if

      *              no resource with this name is found

      * @throws  NullPointerException If {@code name} is {@code null}

      * @since  JDK1.1

      */

      public InputStream getResourceAsStream(String name) {

         name = resolveName(name);

         ClassLoader cl = getClassLoader0();

         if (cl==null) {

             // A system class.

             return ClassLoader.getSystemResourceAsStream(name);

         }

         return cl.getResourceAsStream(name);

     }

     /**

      * Finds a resource with a given name.  The rules for searching resources

      * associated with a given class are implemented by the defining

      * {@linkplain ClassLoader class loader} of the class.  This method

      * delegates to this object's class loader.  If this object was loaded by

      * the bootstrap class loader, the method delegates to {@link

      * ClassLoader#getSystemResource}.

      *

      * <p> Before delegation, an absolute resource name is constructed from the

      * given resource name using this algorithm:

      *

      * <ul>

      *

      * <li> If the {@code name} begins with a {@code '/'}

      * (<tt>'&#92;u002f'</tt>), then the absolute name of the resource is the

      * portion of the {@code name} following the {@code '/'}.

      *

      * <li> Otherwise, the absolute name is of the following form:

      *

      * <blockquote>

      *   {@code modified_package_name/name}

      * </blockquote>

      *

      * <p> Where the {@code modified_package_name} is the package name of this

      * object with {@code '/'} substituted for {@code '.'}

      * (<tt>'&#92;u002e'</tt>).

      *

      * </ul>

      *

      * @param  name name of the desired resource

      * @return      A  {@link java.net.URL} object or {@code null} if no

      *              resource with this name is found

      * @since  JDK1.1

      */

     public java.net.URL getResource(String name) {

         name = resolveName(name);

         ClassLoader cl = getClassLoader0();

         if (cl==null) {

             // A system class.

             return ClassLoader.getSystemResource(name);

         }

         return cl.getResource(name);

     }

    /**

      * Add a package name prefix if the name is not absolute Remove leading "/"

      * if name is absolute

      */

     private String resolveName(String name) {

         if (name == null) {

             return name;

         }

         if (!name.startsWith("/")) {

             Class<?> c = this;

             while (c.isArray()) {

                 c = c.getComponentType();

             }

             String baseName = c.getName();

             int index = baseName.lastIndexOf('.');

             if (index != -1) {

                 name = baseName.substring(0, index).replace('.', '/')

                     +"/"+name;

             }

         } else {

             name = name.substring(1);

         }

         return name;

     }

     /**

      * Returns the class loader for the class.  Some implementations may use

      * null to represent the bootstrap class loader. This method will return

      * null in such implementations if this class was loaded by the bootstrap

      * class loader.

      *

      * <p> If a security manager is present, and the caller's class loader is

      * not null and the caller's class loader is not the same as or an ancestor of

      * the class loader for the class whose class loader is requested, then

      * this method calls the security manager's {@code checkPermission}

      * method with a {@code RuntimePermission("getClassLoader")}

      * permission to ensure it's ok to access the class loader for the class.

      *

      * <p>If this object

      * represents a primitive type or void, null is returned.

      *

      * @return  the class loader that loaded the class or interface

      *          represented by this object.

      * @throws SecurityException

      *    if a security manager exists and its

      *    {@code checkPermission} method denies

      *    access to the class loader for the class.

      * @see java.lang.ClassLoader

      * @see SecurityManager#checkPermission

      * @see java.lang.RuntimePermission

      */

     public ClassLoader getClassLoader() {

         throw new SecurityException();

     }

     // Package-private to allow ClassLoader access

     native ClassLoader getClassLoader0();    

     /**

      * Returns the {@code Class} representing the component type of an

      * array.  If this class does not represent an array class this method

      * returns null.

      *

      * @return the {@code Class} representing the component type of this

      * class if this class is an array

      * @see     java.lang.reflect.Array

      * @since JDK1.1

      */

     public native Class<?> getComponentType();

     /**

      * Returns true if and only if this class was declared as an enum in the

      * source code.

      *

      * @return true if and only if this class was declared as an enum in the

      *     source code

      * @since 1.5

      */

     public boolean isEnum() {

         // An enum must both directly extend java.lang.Enum and have

         // the ENUM bit set; classes for specialized enum constants

         // don't do the former.

         return (this.getModifiers() & ENUM) != 0 &&

         this.getSuperclass() == java.lang.Enum.class;

     }

     /**

      * Casts an object to the class or interface represented

      * by this {@code Class} object.

      *

      * @param obj the object to be cast

      * @return the object after casting, or null if obj is null

      *

      * @throws ClassCastException if the object is not

      * null and is not assignable to the type T.

      *

      * @since 1.5

      */

     public T cast(Object obj) {

         if (obj != null && !isInstance(obj))

             throw new ClassCastException(cannotCastMsg(obj));

         return (T) obj;

     }

     private String cannotCastMsg(Object obj) {

         return "Cannot cast " + obj.getClass().getName() + " to " + getName();

     }

     /**

      * Casts this {@code Class} object to represent a subclass of the class

      * represented by the specified class object.  Checks that that the cast

      * is valid, and throws a {@code ClassCastException} if it is not.  If

      * this method succeeds, it always returns a reference to this class object.

      *

      * <p>This method is useful when a client needs to "narrow" the type of

      * a {@code Class} object to pass it to an API that restricts the

      * {@code Class} objects that it is willing to accept.  A cast would

      * generate a compile-time warning, as the correctness of the cast

      * could not be checked at runtime (because generic types are implemented

      * by erasure).

      *

      * @return this {@code Class} object, cast to represent a subclass of

      *    the specified class object.

      * @throws ClassCastException if this {@code Class} object does not

      *    represent a subclass of the specified class (here "subclass" includes

      *    the class itself).

      * @since 1.5

      */

     public <U> Class<? extends U> asSubclass(Class<U> clazz) {

         if (clazz.isAssignableFrom(this))

             return (Class<? extends U>) this;

         else

             throw new ClassCastException(this.toString());

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      * @since 1.5

      */

     public <A extends Annotation> A getAnnotation(Class<A> annotationClass) {

         throw new UnsupportedOperationException();

     }

     /**

      * @throws NullPointerException {@inheritDoc}

      * @since 1.5

      */

     public boolean isAnnotationPresent(

         Class<? extends Annotation> annotationClass) {

         if (annotationClass == null)

             throw new NullPointerException();

         return getAnnotation(annotationClass) != null;

     }

     /**

      * @since 1.5

      */

     public Annotation[] getAnnotations() {

         throw new UnsupportedOperationException();

     }

     /**

      * @since 1.5

      */

     public Annotation[] getDeclaredAnnotations()  {

         throw new UnsupportedOperationException();

     }

     static Class getPrimitiveClass(String type) {

         // XXX

         return Object.class;

     }

     public boolean desiredAssertionStatus() {

         return false;

     }

 }