1 /*
 2  * Copyright (c) 2003, 2026, 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     4193200
27  * @summary Basic test for Collections.frequency
28  * @author  Josh Bloch
29  * @library /test/lib
30  */
31 
32 import jdk.test.lib.valueclass.VClass;
33 import java.util.ArrayList;
34 import java.util.Collections;
35 import java.util.LinkedList;
36 import java.util.List;
37 
38 public class Frequency {
39     static final int N = 100;
40 
41     public static void main(String[] args) {
42         test(new ArrayList<Integer>());
43         test(new LinkedList<Integer>());
44         testValue();
45     }
46 
47     static void test(List<Integer> list) {
48         for (int i = 0; i < N; i++)
49             for (int j = 0; j < i; j++)
50                 list.add(i);
51         Collections.shuffle(list);
52 
53         for (int i = 0; i < N; i++)
54             if (Collections.frequency(list, i) != i)
55                 throw new RuntimeException(list.getClass() + ": " + i);
56     }
57 
58     static void testValue() {
59         List<VClass> values = new ArrayList<>();
60         for (int i = 0; i < N; i++)
61             for (int j = 0; j < i; j++)
62                 values.add(new VClass(i, new int[] { i }));
63         Collections.shuffle(values);
64         for (int i = 0; i < N; i++)
65             if (Collections.frequency(values, new VClass(i, new int[] { i })) != i)
66                 throw new RuntimeException("value frequency: " + i);
67     }
68 }
--- EOF ---