1 /*
2  * Copyright (c) 2002, 2013, 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 4593209 8001667
27  * @summary Reverse comparator was subtly broken
28  * @author Josh Bloch
29  */
30 
31 package test.java.util.Collections;
32 
33 import java.io.ByteArrayInputStream;
34 import java.io.ByteArrayOutputStream;
35 import java.io.ObjectInputStream;
36 import java.io.ObjectOutputStream;
37 import java.util.Arrays;
38 import java.util.Collections;
39 import java.util.Comparator;
40 import java.util.List;
41 
42 public class ReverseOrder {
serialBytes(Object o)43     static byte[] serialBytes(Object o) {
44         try {
45             ByteArrayOutputStream bos = new ByteArrayOutputStream();
46             ObjectOutputStream oos = new ObjectOutputStream(bos);
47             oos.writeObject(o);
48             oos.flush();
49             oos.close();
50             return bos.toByteArray();
51         } catch (Throwable t) {
52             throw new Error(t);
53         }
54     }
55 
56     @SuppressWarnings("unchecked")
serialClone(T o)57     static <T> T serialClone(T o) {
58         try {
59             ObjectInputStream ois = new ObjectInputStream
60                 (new ByteArrayInputStream(serialBytes(o)));
61             T clone = (T) ois.readObject();
62             return clone;
63         } catch (Throwable t) {
64             throw new Error(t);
65         }
66     }
67 
main(String[] args)68     public static void main(String[] args) throws Exception {
69         Foo[] a = { new Foo(2), new Foo(3), new Foo(1) };
70         List list = Arrays.asList(a);
71         Comparator cmp = Collections.reverseOrder();
72         Collections.sort(list, cmp);
73 
74         Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) };
75         List goldenList = Arrays.asList(golden);
76         if (!list.equals(goldenList))
77             throw new Exception(list.toString());
78 
79         Comparator clone = serialClone(cmp);
80         List list2 = Arrays.asList(a);
81         Collections.sort(list2, clone);
82         if (!list2.equals(goldenList))
83             throw new Exception(list.toString());
84     }
85 }
86 
87 class Foo implements Comparable {
88     int val;
Foo(int i)89     Foo(int i) { val = i; }
90 
compareTo(Object o)91     public int compareTo(Object o) {
92         Foo f = (Foo)o;
93         return (val < f.val ? Integer.MIN_VALUE : (val == f.val ? 0 : 1));
94     }
95 
equals(Object o)96     public boolean equals(Object o) {
97         return o instanceof Foo && ((Foo)o).val == val;
98     }
99 
hashCode()100     public int hashCode()    { return val; }
101 
toString()102     public String toString() { return Integer.toString(val); }
103 }
104