所需jar:log4j-1.2.17.jar
参考:https://blog.youkuaiyun.com/sunny_na/article/details/55212029
1,日志级别
DEBUG < INFO < WARN < ERROR < FATAL
虽然在代码写的时候你用debug info error都是可以,但是为了方便管理,只有调试的时候才用到日志会用debug,一些信息类的日志记录通常会用info(比如你想看一天有几个用户登录),一些错误的,或者异常信息会用error,比如某个时刻数据库连接出了问题,如果分析日志,直接搜索error开头的就能直接定位到了
log4j.properties
### 设置###
log4j.rootLogger = error,stdout,D,E,F
### 输出信息到控制抬 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
### 输出DEBUG 级别以上的日志到=../logs/debug.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = ../logs/debug.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
### 输出INFO 级别以上的日志到=../logs/info.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = ../logs/info.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = INFO
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
### 输出ERROR 级别以上的日志到=../logs/error.log ###
log4j.appender.F = org.apache.log4j.DailyRollingFileAppender
log4j.appender.F.File =../logs/error.log
log4j.appender.F.Append = true
log4j.appender.F.Threshold = ERROR
log4j.appender.F.layout = org.apache.log4j.PatternLayout
log4j.appender.F.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n