1 /** 2 * Copyright (c) 2004-2011 QOS.ch 3 * All rights reserved. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining 6 * a copy of this software and associated documentation files (the 7 * "Software"), to deal in the Software without restriction, including 8 * without limitation the rights to use, copy, modify, merge, publish, 9 * distribute, sublicense, and/or sell copies of the Software, and to 10 * permit persons to whom the Software is furnished to do so, subject to 11 * the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be 14 * included in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 * 24 */ 25 package org.slf4j.ext; 26 27 import org.apache.commons.lang.text.StrLookup; 28 import org.slf4j.MDC; 29 30 /** 31 * This class can be used with the Commons Lang StrSubstitutor to replace 32 * tokens that occur in Strings with their values in the MDC. 33 * 34 * @author Ralph Goers 35 */ 36 public class MDCStrLookup extends StrLookup { 37 /** 38 * Looks up up a value in the MDC. 39 * 40 * @param key the key to be looked up, may be null 41 * @return the matching value, null if no match 42 */ 43 public String lookup(String key) { 44 if (key == null) { 45 return null; 46 } 47 return MDC.get(key); 48 } 49 } 50
