Source Home >> Java Source 1.6.0 >> java.lang.ClassNotFoundException V 0.09

001/*
002 * @(#)ClassNotFoundException.java	1.21 05/11/17
003 *
004 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
005 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
006 */
007
008package java.lang;
009
010/**
011 * Thrown when an application tries to load in a class through its 
012 * string name using:
013 * <ul>
014 * <li>The <code>forName</code> method in class <code>Class</code>.
015 * <li>The <code>findSystemClass</code> method in class
016 *     <code>ClassLoader</code> .
017 * <li>The <code>loadClass</code> method in class <code>ClassLoader</code>.
018 * </ul>
019 * <p>
020 * but no definition for the class with the specified name could be found. 
021 *
022 * <p>As of release 1.4, this exception has been retrofitted to conform to
023 * the general purpose exception-chaining mechanism.  The "optional exception
024 * that was raised while loading the class" that may be provided at
025 * construction time and accessed via the {@link #getException()} method is
026 * now known as the <i>cause</i>, and may be accessed via the {@link
027 * Throwable#getCause()} method, as well as the aforementioned "legacy method."
028 *
029 * @author  unascribed
030 * @version 1.21, 11/17/05
031 * @see     java.lang.Class#forName(java.lang.String)
032 * @see     java.lang.ClassLoader#findSystemClass(java.lang.String)
033 * @see     java.lang.ClassLoader#loadClass(java.lang.String, boolean)
034 * @since   JDK1.0
035 */
036public class ClassNotFoundException extends Exception {
037    /**
038     * use serialVersionUID from JDK 1.1.X for interoperability
039     */
040     private static final long serialVersionUID = 9176873029745254542L;
041
042    /**
043     * This field holds the exception ex if the 
044     * ClassNotFoundException(String s, Throwable ex) constructor was
045     * used to instantiate the object
046     * @serial 
047     * @since 1.2
048     */
049    private Throwable ex;
050
051    /**
052     * Constructs a <code>ClassNotFoundException</code> with no detail message.
053     */
054    public ClassNotFoundException() {
055	super((Throwable)null);  // Disallow initCause
056    }
057
058    /**
059     * Constructs a <code>ClassNotFoundException</code> with the 
060     * specified detail message. 
061     *
062     * @param   s   the detail message.
063     */
064    public ClassNotFoundException(String s) {
065	super(s, null);  //  Disallow initCause
066    }
067
068    /**
069     * Constructs a <code>ClassNotFoundException</code> with the
070     * specified detail message and optional exception that was
071     * raised while loading the class.
072     *
073     * @param s the detail message
074     * @param ex the exception that was raised while loading the class
075     * @since 1.2
076     */
077    public ClassNotFoundException(String s, Throwable ex) {
078	super(s, null);  //  Disallow initCause
079	this.ex = ex;
080    }
081
082    /**
083     * Returns the exception that was raised if an error occurred while
084     * attempting to load the class. Otherwise, returns <tt>null</tt>.
085     *
086     * <p>This method predates the general-purpose exception chaining facility.
087     * The {@link Throwable#getCause()} method is now the preferred means of
088     * obtaining this information.
089     *
090     * @return the <code>Exception</code> that was raised while loading a class
091     * @since 1.2
092     */
093    public Throwable getException() {
094        return ex;
095    }
096
097    /**
098     * Returns the cause of this exception (the exception that was raised
099     * if an error occurred while attempting to load the class; otherwise
100     * <tt>null</tt>).
101     *
102     * @return  the cause of this exception.
103     * @since   1.4
104     */
105    public Throwable getCause() {
106        return ex;
107    }
108}