log4j配置文件详解
https://blog.csdn.net/azheng270/article/details/2173430/
### set log levels ###
log4j.rootLogger = debug,stdout,D,E
### 输出到控制台 ###
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 = %d{yyyy-MM-dd HH:mm:ss,SSS} [%C %M] %p %m%n
## 输出DEBUG级别以上的日志
log4j.appender.stdout.Threshold = INFO
### 输出到日志文件 ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = logs/AnalyzeRelation.log
log4j.appender.D.Append = true
## 输出DEBUG级别以上的日志
log4j.appender.D.Threshold = INFO
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss,SSS} [%C %M] %p %m%n
### 保存异常信息到单独文件 ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
## 异常日志文件名
log4j.appender.E.File = logs/AnalyzeRelation_Error.log
log4j.appender.E.Append = true
## 只输出ERROR级别以上的日志!!!
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %d{yyyy-MM-dd HH:mm:ss,SSS} [%C %M] %p %m%n
# Print only messages of level WARN or above in the package com.foo.
log4j.logger.com.foo=WARN
