nullpointerexception.java

来自「《移动Agent技术》一书的所有章节源代码。」· Java 代码 · 共 67 行

/*
 * @(#)NullPointerException.java	1.11 97/01/20
 * 
 * Copyright (c) 1995, 1996 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the confidential and proprietary information of Sun
 * Microsystems, Inc. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with Sun.
 * 
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
 * SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 * PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR ANY DAMAGES
 * SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
 * THIS SOFTWARE OR ITS DERIVATIVES.
 * 
 * CopyrightVersion 1.1_beta
 * 
 */

package java.lang;

/**
 * Thrown when an application attempts to use <code>null</code> in a 
 * case where an object is required. These include: 
 * <ul>
 * <li>Calling the instance method of a <code>null</code> object. 
 * <li>Accessing or modifying the field of a <code>null</code> object. 
 * <li>Taking the length of <code>null</code> as if it were an array. 
 * <li>Accessing or modifying the slots of <code>null</code> as if it 
 *     were an array. 
 * <li>Throwing <code>null</code> as if it were a <code>Throwable</code> 
 *     value. 
 * </ul>
 * <p>
 * Applications should throw instances of this class to indicate 
 * other illegal uses of the <code>null</code> object. 
 *
 * @author  unascribed
 * @version 1.11, 01/20/97
 * @since   JDK1.0
 */
public
class NullPointerException extends RuntimeException {
    /**
     * Constructs a <code>NullPointerException</code> with no detail message.
     *
     * @since   JDK1.0
     */
    public NullPointerException() {
	super();
    }

    /**
     * Constructs a <code>NullPointerException</code> with the specified 
     * detail message. 
     *
     * @param   s   the detail message.
     * @since   JDK1.0
     */
    public NullPointerException(String s) {
	super(s);
    }
}