1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. 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.log4j.helpers;
19
20 import java.util.Hashtable;
21
22 /**
23 <code>ThreadLocalMap</code> extends {@link InheritableThreadLocal}
24 to bequeath a copy of the hashtable of the MDC of the parent
25 thread.
26
27 @author Ceki Gülcü
28 @since 1.2
29 */
30 final public class ThreadLocalMap extends InheritableThreadLocal {
31
32 public
33 final
34 Object childValue(Object parentValue) {
35 Hashtable ht = (Hashtable) parentValue;
36 if(ht != null) {
37 return ht.clone();
38 } else {
39 return null;
40 }
41 }
42 }
43