/*

 * Copyright 1995-2004 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package java.lang;

/**

 * Thrown when an application tries to load in a class through its

 * string name using:

 * <ul>

 * <li>The <code>forName</code> method in class <code>Class</code>.

 * <li>The <code>findSystemClass</code> method in class

 *     <code>ClassLoader</code> .

 * <li>The <code>loadClass</code> method in class <code>ClassLoader</code>.

 * </ul>

 * <p>

 * but no definition for the class with the specified name could be found.

 *

 * <p>As of release 1.4, this exception has been retrofitted to conform to

 * the general purpose exception-chaining mechanism.  The "optional exception

 * that was raised while loading the class" that may be provided at

 * construction time and accessed via the {@link #getException()} method is

 * now known as the <i>cause</i>, and may be accessed via the {@link

 * Throwable#getCause()} method, as well as the aforementioned "legacy method."

 *

 * @author  unascribed

 * @see     java.lang.Class#forName(java.lang.String)

 * @see     java.lang.ClassLoader#findSystemClass(java.lang.String)

 * @see     java.lang.ClassLoader#loadClass(java.lang.String, boolean)

 * @since   JDK1.0

 */

public class ClassNotFoundException extends Exception {

    /**

     * use serialVersionUID from JDK 1.1.X for interoperability

     */

     private static final long serialVersionUID = 9176873029745254542L;

    /**

     * This field holds the exception ex if the

     * ClassNotFoundException(String s, Throwable ex) constructor was

     * used to instantiate the object

     * @serial

     * @since 1.2

     */

    private Throwable ex;

    /**

     * Constructs a <code>ClassNotFoundException</code> with no detail message.

     */

    public ClassNotFoundException() {

        super((Throwable)null);  // Disallow initCause

    }

    /**

     * Constructs a <code>ClassNotFoundException</code> with the

     * specified detail message.

     *

     * @param   s   the detail message.

     */

    public ClassNotFoundException(String s) {

        super(s, null);  //  Disallow initCause

    }

    /**

     * Constructs a <code>ClassNotFoundException</code> with the

     * specified detail message and optional exception that was

     * raised while loading the class.

     *

     * @param s the detail message

     * @param ex the exception that was raised while loading the class

     * @since 1.2

     */

    public ClassNotFoundException(String s, Throwable ex) {

        super(s, null);  //  Disallow initCause

        this.ex = ex;

    }

    /**

     * Returns the exception that was raised if an error occurred while

     * attempting to load the class. Otherwise, returns <tt>null</tt>.

     *

     * <p>This method predates the general-purpose exception chaining facility.

     * The {@link Throwable#getCause()} method is now the preferred means of

     * obtaining this information.

     *

     * @return the <code>Exception</code> that was raised while loading a class

     * @since 1.2

     */

    public Throwable getException() {

        return ex;

    }

    /**

     * Returns the cause of this exception (the exception that was raised

     * if an error occurred while attempting to load the class; otherwise

     * <tt>null</tt>).

     *

     * @return  the cause of this exception.

     * @since   1.4

     */

    public Throwable getCause() {

        return ex;

    }

}