| /* |
| * Copyright (c) 2012, 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. |
| * |
| * 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. |
| */ |
| |
| /** |
| * @test |
| * @bug 7173432 |
| * @summary If the key to be inserted into a HashMap is null and the table |
| * needs to be resized as part of the insertion then addEntry will try to |
| * recalculate the hash of a null key. This will fail with an NPE. |
| */ |
| |
| import java.util.*; |
| |
| public class NullKeyAtResize { |
| public static void main(String[] args) throws Exception { |
| List<Object> old_order = new ArrayList<>(); |
| Map<Object,Object> m = new HashMap<>(16); |
| int number = 0; |
| while(number < 100000) { |
| m.put(null,null); // try to put in null. This may cause resize. |
| m.remove(null); // remove it. |
| Integer adding = (number += 100); |
| m.put(adding, null); // try to put in a number. This wont cause resize. |
| List<Object> new_order = new ArrayList<>(); |
| new_order.addAll(m.keySet()); |
| new_order.remove(adding); |
| if(!old_order.equals(new_order)) { |
| // we resized and didn't crash. |
| System.out.println("Encountered resize after " + (number / 100) + " iterations"); |
| break; |
| } |
| // remember this order for the next time around. |
| old_order.clear(); |
| old_order.addAll(m.keySet()); |
| } |
| if(number == 100000) { |
| throw new Error("Resize never occurred"); |
| } |
| } |
| } |