| 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 }