| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package com.opensymphony.xwork2.util; |
| |
| import java.util.List; |
| import java.util.concurrent.CopyOnWriteArrayList; |
| |
| |
| /** |
| * A Stack that is implemented using a List. |
| * |
| * @author plightbo |
| * @version $Revision$ |
| */ |
| public class CompoundRoot extends CopyOnWriteArrayList<Object> { |
| |
| private static final long serialVersionUID = 8563229069192473995L; |
| |
| public CompoundRoot() { |
| } |
| |
| public CompoundRoot(List<?> list) { |
| super(list); |
| } |
| |
| |
| public CompoundRoot cutStack(int index) { |
| return new CompoundRoot(subList(index, size())); |
| } |
| |
| public Object peek() { |
| return get(0); |
| } |
| |
| public Object pop() { |
| return remove(0); |
| } |
| |
| public void push(Object o) { |
| add(0, o); |
| } |
| } |