1/*
2 * Copyright (c) 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 * Portions Copyright (c) 2013 IBM Corporation
26 */
27
28/**
29 * @test
30 * @bug 8019381
31 * @summary Verify that we do not get exception when we override isEmpty()
32 *          in a subclass of HashMap
33 * @author zhangshj@linux.vnet.ibm.com
34 */
35
36import java.util.function.BiFunction;
37import java.util.HashMap;
38
39public class OverrideIsEmpty {
40    public static class NotEmptyHashMap<K,V> extends HashMap<K,V> {
41        private K alwaysExistingKey;
42        private V alwaysExistingValue;
43
44        @Override
45        public V get(Object key) {
46            if (key == alwaysExistingKey) {
47                return alwaysExistingValue;
48            }
49            return super.get(key);
50        }
51
52        @Override
53        public int size() {
54            return super.size() + 1;
55        }
56
57        @Override
58        public boolean isEmpty() {
59            return size() == 0;
60        }
61    }
62
63    public static void main(String[] args) {
64        NotEmptyHashMap<Object, Object> map = new NotEmptyHashMap<>();
65        Object key = new Object();
66        Object value = new Object();
67        map.get(key);
68        map.remove(key);
69        map.replace(key, value, null);
70        map.replace(key, value);
71        map.computeIfPresent(key, new BiFunction<Object, Object, Object>() {
72            public Object apply(Object key, Object oldValue) {
73                return oldValue;
74            }
75        });
76    }
77}
78
79