1 /**
2 * Logback: the reliable, generic, fast and flexible logging framework.
3 * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
4 *
5 * This program and the accompanying materials are dual-licensed under
6 * either the terms of the Eclipse Public License v1.0 as published by
7 * the Eclipse Foundation
8 *
9 * or (per the licensee's choosing)
10 *
11 * under the terms of the GNU Lesser General Public License version 2.1
12 * as published by the Free Software Foundation.
13 */
14 package ch.qos.logback.classic.util;
15
16 import java.util.HashMap;
17
18 /**
19 * This class extends InheritableThreadLocal so that children threads get a copy
20 * of the parent's hashmap.
21 *
22 * @author Ceki Gülcü
23 */
24 public class CopyOnInheritThreadLocal extends
25 InheritableThreadLocal<HashMap<String, String>> {
26
27 /**
28 * Child threads should get a copy of the parent's hashmap.
29 */
30 @Override
31 protected HashMap<String, String> childValue(
32 HashMap<String, String> parentValue) {
33 if (parentValue == null) {
34 return null;
35 } else {
36 HashMap<String, String> hm = new HashMap<String, String>(parentValue);
37 return hm;
38 }
39 }
40
41 }