Java tutorial
/* * Copyright (c) 1994, 2011, 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; /** * Thrown when an application attempts to use {@code null} in a * case where an object is required. These include: * <ul> * <li>Calling the instance method of a {@code null} object. * <li>Accessing or modifying the field of a {@code null} object. * <li>Taking the length of {@code null} as if it were an array. * <li>Accessing or modifying the slots of {@code null} as if it * were an array. * <li>Throwing {@code null} as if it were a {@code Throwable} * value. * </ul> * <p> * Applications should throw instances of this class to indicate * other illegal uses of the {@code null} object. * * {@code NullPointerException} objects may be constructed by the * virtual machine as if {@linkplain Throwable#Throwable(String, * Throwable, boolean, boolean) suppression were disabled and/or the * stack trace was not writable}. * * @author unascribed * @since 1.0 */ public class NullPointerException extends RuntimeException { private static final long serialVersionUID = 5162710183389028792L; /** * Constructs a {@code NullPointerException} with no detail message. */ public NullPointerException() { super(); } /** * Constructs a {@code NullPointerException} with the specified * detail message. * * @param s the detail message. */ public NullPointerException(String s) { super(s); } }