001    /**
002     * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved.
003     *
004     * The contents of this file are subject to the terms of the Liferay Enterprise
005     * Subscription License ("License"). You may not use this file except in
006     * compliance with the License. You can obtain a copy of the License by
007     * contacting Liferay, Inc. See the License for the specific language governing
008     * permissions and limitations under the License, including but not limited to
009     * distribution rights of the Software.
010     *
011     *
012     *
013     */
014    
015    package com.liferay.util;
016    
017    /**
018     * @author Brian Wing Shun Chan
019     */
020    public class FiniteUniqueStack<E> extends FiniteStack<E> {
021    
022            public FiniteUniqueStack(int maxSize) {
023                    super(maxSize);
024            }
025    
026            public E push(E item) {
027                    if (!contains(item)) {
028                            super.push(item);
029                    }
030                    else {
031                            if (!item.equals(peek())) {
032                                    remove(item);
033                                    super.push(item);
034                            }
035                    }
036    
037                    return item;
038            }
039    
040    }