/*

 * 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;

import org.apidesign.bck2brwsr.core.JavaScriptBody;

/**

 * 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>

     *

     */

    @JavaScriptBody(args = "self", body =

          "var inst = self.cnstr();"

        + "inst.consV(inst);"

        + "return inst;"

    )

    public T newInstance()

        throws InstantiationException, IllegalAccessException

    {

        throw new UnsupportedOperationException();

    }

    /**

     * 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 boolean isArray() {

        return false;

    }

    /**

     * 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() {

        return jvmName().replace('/', '.');

    }

    @JavaScriptBody(args = "self", body = "return self.jvmName;")

    private native String jvmName();

    /**

     * 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.

     */

    @JavaScriptBody(args = "self", body = "return self.superclass;")

    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() {

        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 IllegalStateException("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);

    }

    /**

     * Returns the "simple binary name" of the underlying class, i.e.,

     * the binary name without the leading enclosing class name.

     * Returns {@code null} if the underlying class is a top level

     * class.

     */

    private String getSimpleBinaryName() {

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

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

            return null;

        // Otherwise, strip the enclosing class' name

        try {

            return getName().substring(enclosingClass.getName().length());

        } catch (IndexOutOfBoundsException ex) {

            throw new IllegalStateException("Malformed class name");

        }

    }

    /**

     * 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() {

        if (isArray()) {

            String canonicalName = getComponentType().getCanonicalName();

            if (canonicalName != null)

                return canonicalName + "[]";

            else

                return null;

        }

//        if (isLocalOrAnonymousClass())

//            return null;

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

        Class<?> enclosingClass = null;

        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 Class<?> getComponentType() {

        return null;

    }

    /**

     * 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

     */

    @JavaScriptBody(args = { "self", "ac" }, 

        body = 

          "if (self.anno) {"

        + "  return self.anno['L' + ac.jvmName + ';'];"

        + "}"

    )

    private Object getAnnotationData(Class<?> annotationClass) {

        throw new UnsupportedOperationException();

    }

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

        Object data = getAnnotationData(annotationClass);

        return data == null ? null : AnnotationImpl.create(annotationClass, data);

    }

    /**

     * @throws NullPointerException {@inheritDoc}

     * @since 1.5

     */

    @JavaScriptBody(args = { "self", "ac" }, 

        body = "if (self.anno && self.anno['L' + ac.jvmName + ';']) { return true; }"

        + "else return false;"

    )

    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;

    }

}