摘要：
--配置日志start--˃4.
1.引入log4j-xxx.jar包，buildpath.
2.在项目的根目录下新建resources名的文件夹，注意是source folder，并新建log4j.properties文件
3.在log4j.properties中配置：
#LOG_DIR:/usr/local/.../logs
LOG_DIR = E:\logs
#Level:ERROR,WARN,INFO,DEBUG
log4j.rootLogger = DEBUG,Console,FileInfo,FileError
log4j.appender.Console = org.apache.log4j.ConsoleAppender
log4j.appender.Console.Threshold = DEBUG
log4j.appender.Console.ImmediateFlush = true
log4j.appender.Console.Target = SYSTEM_OUT
log4j.appender.Console.layout = org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
log4j.appender.FileInfo = org.apache.log4j.DailyRollingFileAppender
log4j.appender.FileInfo.Threshold = INFO
log4j.appender.FileInfo.ImmediateFlush = true
log4j.appender.FileInfo.Append = true
log4j.appender.FileInfo.DatePattern = '_'yyyy-MM-dd'.log'
log4j.appender.FileInfo.encoding=UTF-8
log4j.appender.FileInfo.File = ${LOG_DIR}/info
log4j.appender.FileInfo.layout = org.apache.log4j.PatternLayout
log4j.appender.FileInfo.layout.ConversionPattern = [%-5p][%d{ISO8601}]%m%n
log4j.appender.FileError = org.apache.log4j.DailyRollingFileAppender
log4j.appender.FileError.Threshold = ERROR
log4j.appender.FileError.ImmediateFlush = true
log4j.appender.FileError.Append = true
log4j.appender.FileError.DatePattern = '_'yyyy-MM-dd'.log'
log4j.appender.FileError.encoding=UTF-8
log4j.appender.FileError.File = ${LOG_DIR}/error
log4j.appender.FileError.layout = org.apache.log4j.PatternLayout
log4j.appender.FileError.layout.ConversionPattern = [%-5p][%d{ISO8601}]%m%n
log4j.appender.cn.yivi.service.pay = info,pay
log4j.additivity.cn.yivi.service.pay = false
log4j.appender.pay = org.apache.log4j.DailyRollingFileAppender
log4j.appender.pay.Threshold = WARN
log4j.appender.pay.ImmediateFlush = true
log4j.appender.pay.Append = true
log4j.appender.pay.DatePattern = '_'yyyy-MM-dd'.log'
log4j.appender.pay.encoding=UTF-8
log4j.appender.pay.File = ${LOG_DIR}/pay
log4j.appender.pay.layout = org.apache.log4j.PatternLayout
log4j.appender.pay.layout.ConversionPattern = [%-5p][%d{ISO8601}]%m%ntips：日志文件的位置
1）绝对路径
log4j.appender.R.File=D:/log/xxx.log
2）相对路径：
log4j.appender.R.File=../logs/app.log，将日志记录到tomcat下的logs文件夹；
log4j.appender.R.File=logs/app.log，将日志记录到tomcat的bin目录下的logs文件夹；
（3）使用环境变量相对路径法：程序会优先找jvm环境变量，然后再找系统环境变量，来查找配置文件中的变量。
log4j.appender.logfile.File=${user.dir}/logs/app.log，使用tomcat容器时${user.dir}对应tomcat的bin目录；
log4j.appender.logfile.File=${user.home}/logs/app.log，${user.home}对应操作系统当前用户目录；
log4j.appender.logfile.File=${webApp.root}/logs/app.log，${webApp.root}对应当前应用根目录；
4.在web.xml中配置log4j:
<!--配置日志 start--> <!--加载Log4J 配置文件 --> <context-param> <param-name>log4jConfigLocation</param-name> <param-value> classpath:log4j.properties</param-value> </context-param> <context-param> <param-name>log4jRefreshInterval</param-name> <param-value>3000</param-value> </context-param> <listener> <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class> </listener> <!--配置日志 end-->
4.