1 /* 2 * Copyright (c) 2004-2007 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; 26 27 import org.slf4j.helpers.Util; 28 import org.slf4j.impl.StaticLoggerBinder; 29 30 /** 31 * The <code>LoggerFactory</code> is a utility class producing Loggers for 32 * various logging APIs, most notably for log4j, logback and JDK 1.4 logging. 33 * Other implementations such as {@link org.slf4j.impl.NOPLogger NOPLogger} and 34 * {@link org.slf4j.impl.SimpleLogger SimpleLogger} are also supported. 35 * 36 * <p> 37 * <code>LoggerFactory</code> is essentially a wrapper around an 38 * {@link ILoggerFactory} instance bound with <code>LoggerFactory</code> at 39 * compile time. 40 * 41 * <p> 42 * Please note that all methods in <code>LoggerFactory</code> are static. 43 * 44 * @author Ceki Gülcü 45 */ 46 public final class LoggerFactory { 47 48 static ILoggerFactory loggerFactory; 49 50 static final String NO_STATICLOGGERBINDER_URL = "http://www.slf4j.org/codes.html#StaticLoggerBinder"; 51 static final String NULL_LF_URL = "http://www.slf4j.org/codes.html#null_LF"; 52 53 // private constructor prevents instantiation 54 private LoggerFactory() { 55 } 56 57 58 static { 59 try { 60 loggerFactory = StaticLoggerBinder.SINGLETON.getLoggerFactory(); 61 } catch(NoClassDefFoundError ncde) { 62 String msg = ncde.getMessage(); 63 if(msg != null && msg.indexOf("org/slf4j/impl/StaticLoggerBinder") != -1) { 64 Util.reportFailure("Failed to load class \"org.slf4j.impl.StaticLoggerBinder\"."); 65 Util.reportFailure("See "+NO_STATICLOGGERBINDER_URL+" for further details."); 66 67 } 68 throw ncde; 69 } catch (Exception e) { 70 // we should never get here 71 Util.reportFailure("Failed to instantiate logger [" 72 + StaticLoggerBinder.SINGLETON.getLoggerFactoryClassStr() + "]", e); 73 } 74 } 75 76 /** 77 * Return a logger named according to the name parameter using the statically 78 * bound {@link ILoggerFactory} instance. 79 * 80 * @param name 81 * The name of the logger. 82 * @return logger 83 */ 84 public static Logger getLogger(String name) { 85 if(loggerFactory == null) { 86 throw new IllegalStateException("Logging factory implementation cannot be null. See also "+NULL_LF_URL); 87 } 88 return loggerFactory.getLogger(name); 89 } 90 91 /** 92 * Return a logger named corresponding to the class passed as parameter, using 93 * the statically bound {@link ILoggerFactory} instance. 94 * 95 * @param clazz 96 * the returned logger will be named after clazz 97 * @return logger 98 */ 99 public static Logger getLogger(Class clazz) { 100 if(loggerFactory == null) { 101 throw new IllegalStateException("Logging factory implementation cannot be null. See also "+NULL_LF_URL); 102 } 103 return loggerFactory.getLogger(clazz.getName()); 104 } 105 106 /** 107 * Return the {@link ILoggerFactory} instance in use. 108 * 109 * <p>ILoggerFactory instance is bound with this class at compile 110 * time. 111 * 112 * @return the ILoggerFactory instance in use 113 */ 114 public static ILoggerFactory getILoggerFactory() { 115 return loggerFactory; 116 } 117 }