001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017package org.apache.log4j; 018 019import java.util.HashMap; 020import java.util.Hashtable; 021import java.util.Map; 022 023import org.apache.logging.log4j.ThreadContext; 024 025/** 026 * This class behaves just like Log4j's MDC would - and so can cause issues with the redeployment of web 027 * applications if the Objects stored in the threads Map cannot be garbage collected. 028 */ 029public final class MDC { 030 031 032 private static ThreadLocal<Map<String, Object>> localMap = 033 new InheritableThreadLocal<Map<String, Object>>() { 034 @Override 035 protected Map<String, Object> initialValue() { 036 return new HashMap<>(); 037 } 038 039 @Override 040 protected Map<String, Object> childValue(final Map<String, Object> parentValue) { 041 return parentValue == null ? new HashMap<String, Object>() : new HashMap<>(parentValue); 042 } 043 }; 044 045 private MDC() { 046 } 047 048 049 public static void put(final String key, final String value) { 050 localMap.get().put(key, value); 051 ThreadContext.put(key, value); 052 } 053 054 055 public static void put(final String key, final Object value) { 056 localMap.get().put(key, value); 057 ThreadContext.put(key, value.toString()); 058 } 059 060 public static Object get(final String key) { 061 return localMap.get().get(key); 062 } 063 064 public static void remove(final String key) { 065 localMap.get().remove(key); 066 ThreadContext.remove(key); 067 } 068 069 public static void clear() { 070 localMap.get().clear(); 071 ThreadContext.clearMap(); 072 } 073 074 public static Hashtable<String, Object> getContext() { 075 return new Hashtable<>(localMap.get()); 076 } 077}