1 /* 2 * Copyright (c) 1997, 1998, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* @test 25 * @bug 4065313 26 * @summary Ensure that it is okay to replace an object with null. 27 */ 28 import java.io.*; 29 30 class A { } 31 32 class MyObjectOutputStream extends ObjectOutputStream { 33 public MyObjectOutputStream(OutputStream out) throws IOException { 34 super(out); 35 enableReplaceObject(true); 36 } 37 protected Object replaceObject(Object obj) throws IOException { 38 if(obj instanceof A) return null; 39 else return obj; 40 } 41 } 42 43 public class ReplaceWithNull { 44 public static void main(String args[]) throws IOException { 45 A a = new A(); 46 47 MyObjectOutputStream out = 48 new MyObjectOutputStream(new ByteArrayOutputStream()); 49 out.writeObject(a); //raised NullPointerException. 50 out.close(); 51 } 52 }