001/** 002 * Copyright (c) 2004-2011 QOS.ch 003 * All rights reserved. 004 * 005 * Permission is hereby granted, free of charge, to any person obtaining 006 * a copy of this software and associated documentation files (the 007 * "Software"), to deal in the Software without restriction, including 008 * without limitation the rights to use, copy, modify, merge, publish, 009 * distribute, sublicense, and/or sell copies of the Software, and to 010 * permit persons to whom the Software is furnished to do so, subject to 011 * the following conditions: 012 * 013 * The above copyright notice and this permission notice shall be 014 * included in all copies or substantial portions of the Software. 015 * 016 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 017 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 018 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 019 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 020 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 021 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 022 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 023 * 024 */ 025package org.slf4j.reload4j; 026 027import java.util.concurrent.ConcurrentHashMap; 028import java.util.concurrent.ConcurrentMap; 029 030import org.apache.log4j.LogManager; 031import org.slf4j.ILoggerFactory; 032import org.slf4j.Logger; 033import org.slf4j.helpers.Util; 034 035/** 036 * Log4jLoggerFactory is an implementation of {@link ILoggerFactory} returning 037 * the appropriate named {@link Reload4jLoggerAdapter} instance. 038 * 039 * @author Ceki Gülcü 040 */ 041public class Reload4jLoggerFactory implements ILoggerFactory { 042 043 private static final String LOG4J_DELEGATION_LOOP_URL = "http://www.slf4j.org/codes.html#log4jDelegationLoop"; 044 045 // check for delegation loops 046 static { 047 try { 048 Class.forName("org.apache.log4j.Log4jLoggerFactory"); 049 String part1 = "Detected both log4j-over-slf4j.jar AND bound slf4j-log4j12.jar on the class path, preempting StackOverflowError. "; 050 String part2 = "See also " + LOG4J_DELEGATION_LOOP_URL + " for more details."; 051 052 Util.report(part1); 053 Util.report(part2); 054 throw new IllegalStateException(part1 + part2); 055 } catch (ClassNotFoundException e) { 056 // this is the good case 057 } 058 } 059 060 // key: name (String), value: a Log4jLoggerAdapter; 061 ConcurrentMap<String, Logger> loggerMap; 062 063 public Reload4jLoggerFactory() { 064 loggerMap = new ConcurrentHashMap<>(); 065 // force log4j to initialize 066 org.apache.log4j.LogManager.getRootLogger(); 067 } 068 069 /* 070 * (non-Javadoc) 071 * 072 * @see org.slf4j.ILoggerFactory#getLogger(java.lang.String) 073 */ 074 public Logger getLogger(String name) { 075 Logger slf4jLogger = loggerMap.get(name); 076 if (slf4jLogger != null) { 077 return slf4jLogger; 078 } else { 079 org.apache.log4j.Logger log4jLogger; 080 if (name.equalsIgnoreCase(Logger.ROOT_LOGGER_NAME)) 081 log4jLogger = LogManager.getRootLogger(); 082 else 083 log4jLogger = LogManager.getLogger(name); 084 085 Logger newInstance = new Reload4jLoggerAdapter(log4jLogger); 086 Logger oldInstance = loggerMap.putIfAbsent(name, newInstance); 087 return oldInstance == null ? newInstance : oldInstance; 088 } 089 } 090}