| ConcurrentHashSet.java |
1 /**
2 * Copyright (c) 2000-2009 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.portal.kernel.util;
24
25 import java.util.AbstractSet;
26 import java.util.Iterator;
27 import java.util.Map;
28 import java.util.Set;
29 import java.util.concurrent.ConcurrentHashMap;
30
31 /**
32 * <a href="ConcurrentHashSet.java.html"><b><i>View Source</i></b></a>
33 *
34 * @author Brian Wing Shun Chan
35 *
36 */
37 public class ConcurrentHashSet<E> extends AbstractSet<E> {
38
39 public ConcurrentHashSet() {
40 _map = new ConcurrentHashMap<E, String>();
41 }
42
43 public ConcurrentHashSet(int capacity) {
44 _map = new ConcurrentHashMap<E, String>(capacity);
45 }
46
47 public ConcurrentHashSet(Set<E> set) {
48 Iterator<E> itr = set.iterator();
49
50 while (itr.hasNext()) {
51 E e = itr.next();
52
53 _map.put(e, StringPool.BLANK);
54 }
55 }
56
57 public boolean add(E e) {
58 if (_map.put(e, StringPool.BLANK) == null) {
59 return true;
60 }
61 else {
62 return false;
63 }
64 }
65
66 public void clear() {
67 _map.clear();
68 }
69
70 public boolean contains(Object obj) {
71 if (_map.containsKey(obj)) {
72 return true;
73 }
74 else {
75 return false;
76 }
77 }
78
79 public Iterator<E> iterator() {
80 return _map.keySet().iterator();
81 }
82
83 public boolean remove(Object obj) {
84 if (_map.remove(obj) == null) {
85 return false;
86 }
87 else {
88 return true;
89 }
90 }
91
92 public int size() {
93 return _map.size();
94 }
95
96 private Map<E, String> _map;
97
98 }