| ConcurrentHashSet.java |
1 /**
2 * Copyright (c) 2000-2008 Liferay, Inc. All rights reserved.
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 * SOFTWARE.
21 */
22
23 package com.liferay.util;
24
25 import com.liferay.portal.kernel.util.StringPool;
26
27 import java.util.AbstractSet;
28 import java.util.Iterator;
29 import java.util.Map;
30 import java.util.Set;
31 import java.util.concurrent.ConcurrentHashMap;
32
33 /**
34 * <a href="ConcurrentHashSet.java.html"><b><i>View Source</i></b></a>
35 *
36 * @author Brian Wing Shun Chan
37 *
38 */
39 public class ConcurrentHashSet<E> extends AbstractSet<E> {
40
41 public ConcurrentHashSet() {
42 _map = new ConcurrentHashMap<E, String>();
43 }
44
45 public ConcurrentHashSet(int capacity) {
46 _map = new ConcurrentHashMap<E, String>(capacity);
47 }
48
49 public ConcurrentHashSet(Set<E> set) {
50 Iterator<E> itr = set.iterator();
51
52 while (itr.hasNext()) {
53 E e = itr.next();
54
55 _map.put(e, StringPool.BLANK);
56 }
57 }
58
59 public boolean add(E e) {
60 if (_map.put(e, StringPool.BLANK) == null) {
61 return true;
62 }
63 else {
64 return false;
65 }
66 }
67
68 public void clear() {
69 _map.clear();
70 }
71
72 public boolean contains(Object obj) {
73 if (_map.containsKey(obj)) {
74 return true;
75 }
76 else {
77 return false;
78 }
79 }
80
81 public Iterator<E> iterator() {
82 return _map.keySet().iterator();
83 }
84
85 public boolean remove(Object obj) {
86 if (_map.remove(obj) == null) {
87 return false;
88 }
89 else {
90 return true;
91 }
92 }
93
94 public int size() {
95 return _map.size();
96 }
97
98 private Map<E, String> _map;
99
100 }