1 /*
2 * Copyright (c) 2003, 2007, 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 4809442 6366832 4974878 6372554 4890211 6483125
27 * @summary Basic test for Collections.reverseOrder
28 * @author Josh Bloch, Martin Buchholz
29 */
30
31 import java.io.ByteArrayInputStream;
32 import java.io.ByteArrayOutputStream;
33 import java.io.IOException;
34 import java.io.InputStream;
35 import java.io.ObjectInputStream;
36 import java.io.ObjectOutputStream;
37 import java.util.ArrayList;
38 import java.util.Collections;
39 import java.util.Comparator;
40 import java.util.LinkedList;
41 import java.util.List;
42
43 public class ReverseOrder2 {
44 static final int N = 100;
45
46 static void realMain(String[] args) throws Throwable {
47 check(Collections.reverseOrder()
48 == Collections.reverseOrder(null));
49
50 check(Collections.reverseOrder()
51 == reincarnate(Collections.reverseOrder()));
52
53 check(Collections.reverseOrder(Collections.reverseOrder(cmp))
54 == cmp);
55
56 equal(Collections.reverseOrder(cmp),
57 Collections.reverseOrder(cmp));
58
59 equal(Collections.reverseOrder(cmp).hashCode(),
60 Collections.reverseOrder(cmp).hashCode());
61
62 check(Collections.reverseOrder(cmp).hashCode() !=
63 cmp.hashCode());
64
65 test(new ArrayList<String>());
66 test(new LinkedList<String>());
67 test2(new ArrayList<Integer>());
68 test2(new LinkedList<Integer>());
69 }
70
71 static void test(List<String> list) {
72 for (int i = 0; i < N; i++)
73 list.add(String.valueOf(i));
74 Collections.shuffle(list);
75 Collections.sort(list, Collections.reverseOrder(cmp));
76 equal(list, golden);
77 }
78
79 private static Comparator<String> cmp = new Comparator<>() {
80 public int compare(String s1, String s2) {
81 int i1 = Integer.parseInt(s1);
82 int i2 = Integer.parseInt(s2);
83 return (i1 < i2 ? Integer.MIN_VALUE : (i1 == i2 ? 0 : 1));
84 }
85 };
86
87 private static final List<String> golden = new ArrayList<>(N);
88 static {
89 for (int i = N-1; i >= 0; i--)
90 golden.add(String.valueOf(i));
91 }
92
93 static void test2(List<Integer> list) {
94 for (int i = 0; i < N; i++)
95 list.add(i);
96 Collections.shuffle(list);
97 Collections.sort(list, Collections.reverseOrder(null));
98 equal(list, golden2);
99 }
100
101 private static final List<Integer> golden2 = new ArrayList<>(N);
102 static {
103 for (int i = N-1; i >= 0; i--)
104 golden2.add(i);
105 }
106
107 //--------------------- Infrastructure ---------------------------
108 static volatile int passed = 0, failed = 0;
109 static void pass() {passed++;}
110 static void fail() {failed++; Thread.dumpStack();}
111 static void fail(String msg) {System.out.println(msg); fail();}
112 static void unexpected(Throwable t) {failed++; t.printStackTrace();}
113 static void check(boolean cond) {if (cond) pass(); else fail();}
114 static void equal(Object x, Object y) {
115 if (x == null ? y == null : x.equals(y)) pass();
116 else fail(x + " not equal to " + y);}
117 public static void main(String[] args) throws Throwable {
118 try {realMain(args);} catch (Throwable t) {unexpected(t);}
119 System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
120 if (failed > 0) throw new AssertionError("Some tests failed");}
121 static byte[] serializedForm(Object obj) {
122 try {
123 ByteArrayOutputStream baos = new ByteArrayOutputStream();
124 new ObjectOutputStream(baos).writeObject(obj);
125 return baos.toByteArray();
126 } catch (IOException e) {throw new RuntimeException(e);}}
127 static Object readObject(byte[] bytes)
128 throws IOException, ClassNotFoundException {
129 InputStream is = new ByteArrayInputStream(bytes);
130 return new ObjectInputStream(is).readObject();}
131 @SuppressWarnings("unchecked")
132 static <T> T reincarnate(T obj) {
133 try {return (T) readObject(serializedForm(obj));}
134 catch (Exception e) {throw new RuntimeException(e);}}
135 }