FiniteUniqueStack.java |
1 /** 2 * Copyright (c) 2000-2010 Liferay, Inc. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or modify it under 5 * the terms of the GNU Lesser General Public License as published by the Free 6 * Software Foundation; either version 2.1 of the License, or (at your option) 7 * any later version. 8 * 9 * This library is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 11 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more 12 * details. 13 */ 14 15 package com.liferay.util; 16 17 /** 18 * <a href="FiniteUniqueStack.java.html"><b><i>View Source</i></b></a> 19 * 20 * @author Brian Wing Shun Chan 21 */ 22 public class FiniteUniqueStack<E> extends FiniteStack<E> { 23 24 public FiniteUniqueStack(int maxSize) { 25 super(maxSize); 26 } 27 28 public E push(E item) { 29 if (!contains(item)) { 30 super.push(item); 31 } 32 else { 33 if (!item.equals(peek())) { 34 remove(item); 35 super.push(item); 36 } 37 } 38 39 return item; 40 } 41 42 }