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 }