001    /**
002     * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.util;
016    
017    import java.util.LinkedHashMap;
018    import java.util.Map;
019    
020    /**
021     * @author Brian Wing Shun Chan
022     */
023    public class LRUMap<K, V> extends LinkedHashMap<K, V> {
024    
025            public LRUMap(int capacity) {
026                    super(capacity * 3 / 2, 0.75f, true);
027    
028                    _capacity = capacity;
029            }
030    
031            protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
032                    if (size() > _capacity) {
033                            return true;
034                    }
035                    else {
036                            return false;
037                    }
038            }
039    
040            private int _capacity;
041    
042    }