| ConcurrentHashSet.java |
1 /**
2 * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3 *
4 *
5 *
6 *
7 * The contents of this file are subject to the terms of the Liferay Enterprise
8 * Subscription License ("License"). You may not use this file except in
9 * compliance with the License. You can obtain a copy of the License by
10 * contacting Liferay, Inc. See the License for the specific language governing
11 * permissions and limitations under the License, including but not limited to
12 * distribution rights 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 public class ConcurrentHashSet<E> extends AbstractSet<E> {
37
38 public ConcurrentHashSet() {
39 _map = new ConcurrentHashMap<E, String>();
40 }
41
42 public ConcurrentHashSet(int capacity) {
43 _map = new ConcurrentHashMap<E, String>(capacity);
44 }
45
46 public ConcurrentHashSet(Set<E> set) {
47 Iterator<E> itr = set.iterator();
48
49 while (itr.hasNext()) {
50 E e = itr.next();
51
52 _map.put(e, StringPool.BLANK);
53 }
54 }
55
56 public boolean add(E e) {
57 if (_map.put(e, StringPool.BLANK) == null) {
58 return true;
59 }
60 else {
61 return false;
62 }
63 }
64
65 public void clear() {
66 _map.clear();
67 }
68
69 public boolean contains(Object obj) {
70 if (_map.containsKey(obj)) {
71 return true;
72 }
73 else {
74 return false;
75 }
76 }
77
78 public Iterator<E> iterator() {
79 return _map.keySet().iterator();
80 }
81
82 public boolean remove(Object obj) {
83 if (_map.remove(obj) == null) {
84 return false;
85 }
86 else {
87 return true;
88 }
89 }
90
91 public int size() {
92 return _map.size();
93 }
94
95 private Map<E, String> _map;
96
97 }