code: // from gee.cs.oswego.edu/home/jsr166/jsr166
  
  package jsr166tests.jtreg.util.Collections;
  
  /*
   * Copyright 2002 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
   * CA 95054 USA or visit www.sun.com if you need additional information or
   * have any questions.
   */
  
  /*
   * @test
   * @bug 4593209
   * @summary Reverse comparator was subtly broken
   * @author Josh bloch
   */
  
  import java.util.*;
  
  public class ReverseOrder {
      public static void main(String[] args) throws Exception {
          Foo[] a = { new Foo(2), new Foo(3), new Foo(1) };
          List list = Arrays.asList(a);
          Collections.sort(list, Collections.reverseOrder());
  
          Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) };
          List goldenList = Arrays.asList(golden);
          if (!list.equals(goldenList))
              throw new Exception(list.toString());
      }
  }
  
  class Foo implements Comparable {
      int val;
      Foo(int i) { val = i; }
  
      public int compareTo(Object o) {
          Foo f = (Foo)o;
          return (val < f.val ? Integer.MIN_VALUE : (val == f.val ? 0 : 1));
      }
  
      public boolean equals(Object o) {
          return o instanceof Foo && ((Foo)o).val == val;
      }
  
      public int hashCode()    { return val; }
  
      public String toString() { return Integer.toString(val); }
  }
  