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 package org.apache.logging.log4j.spi; 18 19 import java.util.Map; 20 21 /** 22 * Service provider interface to implement custom MDC behavior for {@link org.apache.logging.log4j.ThreadContext}. 23 */ 24 public interface ThreadContextMap { 25 /** 26 * Put a context value (the <code>o</code> parameter) as identified 27 * with the <code>key</code> parameter into the current thread's 28 * context map. 29 * 30 * <p>If the current thread does not have a context map it is 31 * created as a side effect.</p> 32 * @param key The key name. 33 * @param value The key value. 34 */ 35 void put(final String key, final String value); 36 37 /** 38 * Get the context identified by the <code>key</code> parameter. 39 * 40 * <p>This method has no side effects.</p> 41 * @param key The key to locate. 42 * @return The value associated with the key or null. 43 */ 44 String get(final String key); 45 46 /** 47 * Remove the the context identified by the <code>key</code> 48 * parameter. 49 * @param key The key to remove. 50 */ 51 void remove(final String key); 52 53 /** 54 * Clear the context. 55 */ 56 void clear(); 57 58 /** 59 * Determine if the key is in the context. 60 * @param key The key to locate. 61 * @return True if the key is in the context, false otherwise. 62 */ 63 boolean containsKey(final String key); 64 65 /** 66 * Get a non-{@code null} mutable copy of current thread's context Map. 67 * @return a mutable copy of the context. 68 */ 69 Map<String, String> getCopy(); 70 71 /** 72 * Return an immutable view on the context Map or {@code null} if the context map is empty. 73 * @return an immutable context Map or {@code null}. 74 */ 75 Map<String, String> getImmutableMapOrNull(); 76 77 /** 78 * Returns true if the Map is empty. 79 * @return true if the Map is empty, false otherwise. 80 */ 81 boolean isEmpty(); 82 }