步骤：
1. 在Maven的porn.xml 文件中添加dependency如下
1 <dependency> 2 <groupId>org.slf4j</groupId> 3 <artifactId>slf4j-log4j12</artifactId> 4 <version>1.7.2</version> 5 </dependency>
之后就会添加三个包 slf4j-api-1.6.1.jar、slf4j-log4j12-1.7.2.jar、log4j-1.2.17.jar
2. 之后在项目下添加log4j.properties
1 #config root logger 2 log4j.rootLogger = INFO,system.out 3 log4j.appender.system.out=org.apache.log4j.ConsoleAppender 4 log4j.appender.system.out.layout=org.apache.log4j.PatternLayout 5 log4j.appender.system.out.layout.ConversionPattern=MINAServer Logger-->%5p{%F:%L}-%m%n 6 7 #config this Project.file logger 8 log4j.logger.thisProject.file=INFO,thisProject.file.out 9 log4j.appender.thisProject.file.out=org.apache.log4j.DailyRollingFileAppender 10 log4j.appender.thisProject.file.out.File=logContentFile.log 11 log4j.appender.thisProject.file.out.layout=org.apache.log4j.PatternLayout
3. 在代码中添加
private static final Logger logger = LoggerFactory.getLogger(MINAServer.class);
如果要输出到文件系统
1 log4j.rootLogger=INFO,R,stdout 2 3 log4j.appender.stdout=org.apache.log4j.ConsoleAppender 4 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout 5 log4j.appender.stdout.layout.ConversionPattern=Logger-->%5p{%F:%L}-%m%n 6 7 log4j.appender.R=org.apache.log4j.DailyRollingFileAppender 8 log4j.appender.R.File=../logs/log 9 log4j.appender.R.layout=org.apache.log4j.PatternLayout 10 log4j.appender.R.layout.ConversionPattern=Logger-->%5p{%F:%L}-%m%n
每天产生一个log的配置方法：
log4j.rootLogger=DEBUG,DAILY_FILE
log4j.appender.DAILY_FILE=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DAILY_FILE.file=${user.home}/logs/logging.log4j
log4j.appender.DAILY_FILE.DatePattern='_'yyyy-MM-dd'.log'
log4j.appender.DAILY_FILE.ImmediateFlush=true
log4j.appender.DAILY_FILE.Append=true
log4j.appender.DAILY_FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.DAILY_FILE.layout.ConversionPattern=%d %5p [%t] (%F:%L) - %m%n
转载：http://blog.csdn.net/anialy/article/details/8529188