首先导入两个包: commons-logging.jar log4j-1.2.12.jar
在src下编写3个 properties文件
1.log4j.properties 下面是内容
##LOGGERS
#define a logger
log4j.rootLogger=INFO,console,file
##APPENDERS
#define an appender named console
log4j.appender.console=org.apache.log4j.ConsoleAppender
#define an appender named file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=d:/demo_log.txt
#set the log's size
log4j.appender.file.MaxFileSize=1000KB
log4j.appender.file.MaxBackupIndex=20
##LAYOUTS
#assign a SimpleLayout to console appender
log4j.appender.console.layout=org.apache.log4j.SimpleLayout
#assign a PatternLayout to file appender
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=[%-5p][%d{yyyy-MM-dd HH:mm:ss}]%m%n
2.
simplelog.properties下面是内容
log.apache.commons.logging.simplelog.defaultlog=info
3.
commons-logging.properties下面是内容
##set Log as Log4J
org.apache.commons.logging.Log=org.apache.commons.logging.impl.Log4JLogger