log4j.properties，通常配置：

log4j.properties，通常配置：（网上流传大多有问题，特声明一下）

 ### set log levels ###
log4j.rootLogger = debug, stdout, D, E


### console ###
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}] [%t] (%F:%L) -%m%n
### debug file ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File=${catalina.home}/logs/kepu925.log
log4j.appender.D.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = [%5p] [%-d{yyyy-MM-dd HH:mm:ss}] [%t] (%F:%L) -%m%n
### error for sigle file ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File=${catalina.home}/logs/kepu925_error.log
log4j.appender.E.DatePattern='.'yyyy-MM-dd'.log'
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = [%5p] [%-d{yyyy-MM-dd HH:mm:ss}] [%t] (%F:%L) -%m%n