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.core.lookup; 18 19 import org.apache.logging.log4j.ThreadContext; 20 import org.apache.logging.log4j.core.LogEvent; 21 import org.apache.logging.log4j.core.config.plugins.Plugin; 22 23 /** 24 * Looks up keys from system properties. 25 */ 26 @Plugin(name = "ctx", category = "Lookup") 27 public class ContextMapLookup implements StrLookup { 28 29 /** 30 * Lookup the value from the ThreadContext Map. 31 * @param key the key to be looked up, may be null 32 * @return The value associated with the key. 33 */ 34 @Override 35 public String lookup(final String key) { 36 return ThreadContext.get(key); 37 } 38 39 /** 40 * Lookup the value from the ThreadContext Map. 41 * @param event The current LogEvent. 42 * @param key the key to be looked up, may be null 43 * @return The value associated with the key. 44 */ 45 @Override 46 public String lookup(final LogEvent event, final String key) { 47 return event.getContextMap().get(key); 48 } 49 }