1 /*
   2  * Copyright (c) 2001, 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 /**
  25  * @test
  26  * @bug 4559052
  27  * @summary Hashtable's hashCode method always returns zero(!)
  28  * @author Josh Bloch
  29  */
  30 
  31 import java.util.*;
  32 
  33 public class HashCode {
  34     public static void main(String[] args) throws Exception {
  35         Map m = new Hashtable();
  36         if (m.hashCode() != 0)
  37             throw new Exception("Empty Hashtable has nonzero hashCode.");
  38 
  39         m.put("Joe", "Blow");
  40         if (m.hashCode() != ("Joe".hashCode() ^ "Blow".hashCode()))
  41             throw new Exception("Non-empty Hashtable has wrong hashCode.");
  42     }
  43 }