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 */ ClassNotFoundException()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 */ ClassNotFoundException(String s)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 */ ClassNotFoundException(String s, Throwable ex)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 {@code null}. 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 */ getException()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 * {@code null}). 118 * 119 * @return the cause of this exception. 120 * @since 1.4 121 */ getCause()122 public Throwable getCause() { 123 return ex; 124 } 125 } 126