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 }