log4j 使用方法

1,导入两个jar包：log4j-1.3.15.jar;commons-logging-1.1.1.jar

2,配置文件：log4j.properties

log4j.rootCategory=INFO,A1,A2
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%4p [%t] (%F:%L) - %m%n
log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.Threshold=ERROR
log4j.appender.CONSOLE.Target=System.out
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{ABSOLUTE} %-5p [%c{1}] %m%n

log4j.appender.A2=org.apache.log4j.RollingFileAppender
log4j.appender.A2.File=D:/Qsfs.log
log4j.appender.A2.MaxFileSize = 1KB
log4j.appender.A2.MaxBackupIndex = 3
log4j.appender.A2.layout=org.apache.log4j.PatternLayout
log4j.appender.A2.layout.ConversionPattern=%d{yyyy-MM-dd hh:mm:ss}:%p %t %c - %m%n

3,写java代码时候定义变量

 protected final Log log = LogFactory.getLog(getClass());    

 log.info(XXX);