util/TreeMap/NullAtEnd.java

/*
 * Copyright (c) 2005, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug     5018254
 * @summary Test null-allowing Comparators
 * @author  Martin Buchholz
 */

import java.util.Comparator;
import java.util.SortedMap;
import java.util.TreeMap;

public class NullAtEnd {
    static volatile int passed = 0, failed = 0;

    static void fail(String msg) {
        failed++;
        new AssertionError(msg).printStackTrace();
    }

    static void pass() {
        passed++;
    }

    static void unexpected(Throwable t) {
        failed++;
        t.printStackTrace();
    }

    static void check(boolean condition, String msg) {
        if (condition)
            passed++;
        else
            fail(msg);
    }

    static void check(boolean condition) {
        check(condition, "Assertion failure");
    }

    private static boolean eq(Object x, Object y) {
        return x == null ? y == null : x.equals(y);
    }

    private static final Comparator<String> NULL_AT_END
        = new Comparator<>() {
            /**
             * Allows for nulls.  Null is greater than anything non-null.
             */
            public int compare(String x, String y) {
                if (x == null && y == null) return 0;
                if (x == null && y != null) return 1;
                if (x != null && y == null) return -1;
                return x.compareTo(y);
            }
        };

    public static void main(String[] args) {
        try {
            SortedMap<String,String> m1 = new TreeMap<>(NULL_AT_END);
            check(eq(m1.put("a", "a"), null));
            check(eq(m1.put("b", "b"), null));
            check(eq(m1.put("c", "c"), null));
            check(eq(m1.put(null, "d"), null));

            SortedMap<String,String> m2 = new TreeMap<>(m1);

            check(eq(m1.lastKey(), null));
            check(eq(m1.get(m1.lastKey()), "d"));
            check(eq(m1.remove(m1.lastKey()), "d"));
            check(eq(m1.lastKey(), "c"));

            check(eq(m2.entrySet().toString(), "[a=a, b=b, c=c, null=d]"));

            SortedMap<String,String> m3 = m2.tailMap("b");

            check(eq(m3.lastKey(), null));
            check(eq(m3.get(m3.lastKey()), "d"));
            check(eq(m3.remove(m3.lastKey()), "d"));
            check(eq(m3.lastKey(), "c"));

        } catch (Throwable t) { unexpected(t); }

        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
        if (failed > 0) throw new Error("Some tests failed");
    }
}
Revision:	1.4
Committed:	Mon Jan 8 03:12:03 2018 UTC (6 years, 4 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.3:	+3 -2 lines
Log Message:	organize imports
#	User	Rev	Content
1	jsr166	1.1	/*
2	jsr166	1.2	* Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
3	jsr166	1.1	* 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	jsr166	1.2	* 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	jsr166	1.1	*/
23
24			/*
25			* @test
26			* @bug 5018254
27			* @summary Test null-allowing Comparators
28			* @author Martin Buchholz
29			*/
30
31	jsr166	1.4	import java.util.Comparator;
32			import java.util.SortedMap;
33			import java.util.TreeMap;
34	jsr166	1.1
35			public class NullAtEnd {
36			static volatile int passed = 0, failed = 0;
37
38			static void fail(String msg) {
39			failed++;
40			new AssertionError(msg).printStackTrace();
41			}
42
43			static void pass() {
44			passed++;
45			}
46
47			static void unexpected(Throwable t) {
48			failed++;
49			t.printStackTrace();
50			}
51
52			static void check(boolean condition, String msg) {
53			if (condition)
54			passed++;
55			else
56			fail(msg);
57			}
58
59			static void check(boolean condition) {
60			check(condition, "Assertion failure");
61			}
62
63			private static boolean eq(Object x, Object y) {
64			return x == null ? y == null : x.equals(y);
65			}
66
67			private static final Comparator<String> NULL_AT_END
68	jsr166	1.3	= new Comparator<>() {
69	jsr166	1.1	/**
70			* Allows for nulls. Null is greater than anything non-null.
71			*/
72			public int compare(String x, String y) {
73			if (x == null && y == null) return 0;
74			if (x == null && y != null) return 1;
75			if (x != null && y == null) return -1;
76			return x.compareTo(y);
77			}
78			};
79
80			public static void main(String[] args) {
81			try {
82	jsr166	1.3	SortedMap<String,String> m1 = new TreeMap<>(NULL_AT_END);
83	jsr166	1.1	check(eq(m1.put("a", "a"), null));
84			check(eq(m1.put("b", "b"), null));
85			check(eq(m1.put("c", "c"), null));
86			check(eq(m1.put(null, "d"), null));
87
88	jsr166	1.3	SortedMap<String,String> m2 = new TreeMap<>(m1);
89	jsr166	1.1
90			check(eq(m1.lastKey(), null));
91			check(eq(m1.get(m1.lastKey()), "d"));
92			check(eq(m1.remove(m1.lastKey()), "d"));
93			check(eq(m1.lastKey(), "c"));
94
95			check(eq(m2.entrySet().toString(), "[a=a, b=b, c=c, null=d]"));
96
97			SortedMap<String,String> m3 = m2.tailMap("b");
98
99			check(eq(m3.lastKey(), null));
100			check(eq(m3.get(m3.lastKey()), "d"));
101			check(eq(m3.remove(m3.lastKey()), "d"));
102			check(eq(m3.lastKey(), "c"));
103
104			} catch (Throwable t) { unexpected(t); }
105
106			System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
107			if (failed > 0) throw new Error("Some tests failed");
108			}
109			}