1 /**
2 * Logback: the reliable, generic, fast and flexible logging framework.
3 * Copyright (C) 1999-2015, 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 InheritableThreadLocal<HashMap<String, String>> {
25
26 /**
27 * Child threads should get a copy of the parent's hashmap.
28 */
29 @Override
30 protected HashMap<String, String> childValue(HashMap<String, String> parentValue) {
31 if (parentValue == null) {
32 return null;
33 } else {
34 return new HashMap<String, String>(parentValue);
35 }
36 }
37
38 }