1,導入兩個jar包:log4j-1.3.15.jar;commons-logging-1.1.1.jar java
2,配置文件:log4j.properties apache
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 app
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 get
3,寫java代碼時候定義變量 io
protected final Log log = LogFactory.getLog(getClass()); 變量
log.info(XXX); 配置