1/*
2 * Copyright (c) 2005, 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     5018254
27 * @summary Test null-allowing Comparators
28 * @author  Martin Buchholz
29 */
30
31import java.util.*;
32import java.util.concurrent.*;
33
34public class NullAtEnd {
35    static volatile int passed = 0, failed = 0;
36
37    static void fail(String msg) {
38        failed++;
39        new AssertionError(msg).printStackTrace();
40    }
41
42    static void pass() {
43        passed++;
44    }
45
46    static void unexpected(Throwable t) {
47        failed++;
48        t.printStackTrace();
49    }
50
51    static void check(boolean condition, String msg) {
52        if (condition)
53            passed++;
54        else
55            fail(msg);
56    }
57
58    static void check(boolean condition) {
59        check(condition, "Assertion failure");
60    }
61
62    private static boolean eq(Object x, Object y) {
63        return x == null ? y == null : x.equals(y);
64    }
65
66    private static final Comparator<String> NULL_AT_END
67        = new Comparator<>() {
68            /**
69             * Allows for nulls.  Null is greater than anything non-null.
70             */
71            public int compare(String x, String y) {
72                if (x == null && y == null) return 0;
73                if (x == null && y != null) return 1;
74                if (x != null && y == null) return -1;
75                return x.compareTo(y);
76            }
77        };
78
79    public static void main(String[] args) {
80        try {
81            SortedMap<String,String> m1 = new TreeMap<>(NULL_AT_END);
82            check(eq(m1.put("a", "a"), null));
83            check(eq(m1.put("b", "b"), null));
84            check(eq(m1.put("c", "c"), null));
85            check(eq(m1.put(null, "d"), null));
86
87            SortedMap<String,String> m2 = new TreeMap<>(m1);
88
89            check(eq(m1.lastKey(), null));
90            check(eq(m1.get(m1.lastKey()), "d"));
91            check(eq(m1.remove(m1.lastKey()), "d"));
92            check(eq(m1.lastKey(), "c"));
93
94            check(eq(m2.entrySet().toString(), "[a=a, b=b, c=c, null=d]"));
95
96            SortedMap<String,String> m3 = m2.tailMap("b");
97
98            check(eq(m3.lastKey(), null));
99            check(eq(m3.get(m3.lastKey()), "d"));
100            check(eq(m3.remove(m3.lastKey()), "d"));
101            check(eq(m3.lastKey(), "c"));
102
103        } catch (Throwable t) { unexpected(t); }
104
105        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
106        if (failed > 0) throw new Error("Some tests failed");
107    }
108}
109