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Java > Open Source Codes > org > apache > geronimo > core > service > StackThreadLocal


1 /**
2  *
3  * Copyright 2003-2004 The Apache Software Foundation
4  *
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */

17
18 package org.apache.geronimo.core.service;
19
20 import java.util.LinkedList JavaDoc;
21
22 /**
23  *
24  *
25  *
26  * @version $Rev: 46019 $ $Date: 2004-09-14 02:56:06 -0700 (Tue, 14 Sep 2004) $
27  */

28 public class StackThreadLocal {
29     private final ThreadLocal JavaDoc threadLocal = new ThreadLocal JavaDoc() {
30         protected Object JavaDoc initialValue() {
31             return new LinkedList JavaDoc();
32         }
33     };
34
35     public void push(Object JavaDoc value) {
36         if (value == null) {
37             throw new IllegalArgumentException JavaDoc("Value is null");
38         }
39         ((LinkedList JavaDoc) threadLocal.get()).addFirst(value);
40     }
41
42     public Object JavaDoc pop() {
43         LinkedList JavaDoc linkedList = ((LinkedList JavaDoc) threadLocal.get());
44         if (linkedList.isEmpty()) {
45             return null;
46         }
47         return linkedList.removeFirst();
48     }
49
50     public Object JavaDoc peek() {
51         LinkedList JavaDoc linkedList = ((LinkedList JavaDoc) threadLocal.get());
52         if (linkedList.isEmpty()) {
53             return null;
54         }
55         return linkedList.getFirst();
56     }
57 }
58
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