1 /*

     2  * Copyright (c) 1995, 2004, Oracle and/or its affiliates. All rights reserved.

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

     4  *

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

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

     7  * published by the Free Software Foundation.  Oracle designates this

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

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

    10  *

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

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

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

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

    15  * accompanied this code).

    16  *

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

    18  * 2 along with this work; if not, write to the Free Software Foundation,

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

    20  *

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

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

    23  * questions.

    24  */

    25 

    26 package java.lang;

    27 

    28 /**

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

    30  * string name using:

    31  * <ul>

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

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

    34  *     <code>ClassLoader</code> .

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

    36  * </ul>

    37  * <p>

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

    39  *

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

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

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

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

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

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

    46  *

    47  * @author  unascribed

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

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

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

    51  * @since   1.0

    52  */

    53 public class ClassNotFoundException extends ReflectiveOperationException {

    54     /**

    55      * use serialVersionUID from JDK 1.1.X for interoperability

    56      */

    57      private static final long serialVersionUID = 9176873029745254542L;

    58 

    59     /**

    60      * This field holds the exception ex if the

    61      * ClassNotFoundException(String s, Throwable ex) constructor was

    62      * used to instantiate the object

    63      * @serial

    64      * @since 1.2

    65      */

    66     private Throwable ex;

    67 

    68     /**

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

    70      */

    71     public ClassNotFoundException() {

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

    73     }

    74 

    75     /**

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

    77      * specified detail message.

    78      *

    79      * @param   s   the detail message.

    80      */

    81     public ClassNotFoundException(String s) {

    82         super(s, null);  //  Disallow initCause

    83     }

    84 

    85     /**

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

    87      * specified detail message and optional exception that was

    88      * raised while loading the class.

    89      *

    90      * @param s the detail message

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

    92      * @since 1.2

    93      */

    94     public ClassNotFoundException(String s, Throwable ex) {

    95         super(s, null);  //  Disallow initCause

    96         this.ex = ex;

    97     }

    98 

    99     /**

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

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

   102      *

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

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

   105      * obtaining this information.

   106      *

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

   108      * @since 1.2

   109      */

   110     public Throwable getException() {

   111         return ex;

   112     }

   113 

   114     /**

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

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

   117      * <tt>null</tt>).

   118      *

   119      * @return  the cause of this exception.

   120      * @since   1.4

   121      */

   122     public Throwable getCause() {

   123         return ex;

   124     }

   125 }