struts日志配置
一般使用log4j：
首先，需要将log4j-1.2.12.jar拷贝到\WEB-INF\lib中，然后配置属性文件。
属性文件存放在：WEB-INF 下，如下：
commons-logging.properties配置总日志
simplelog.properties配置SimpleLog日志
log4j.properties配置Log4j日志
默认情况下，commons-logging日志选择使用SimpleLog，可以注释掉原来的配置代码，而采用更流行的Log4j。
commons-logging.properties:
Xml代码
## set Log as Log4J
orgorg.apache.commons.logging.Log=org.apache.commons.logging.impl.Log4JLogger
## set Log as SimpleLog
#orgorg.apache.commons.logging.Log=org.apache.commons.logging.impl.SimpleLog
simplelog.properties：
Java代码
org.apache.commons.logging.simplelog.defaultlog = info
log4j.properties：
Java代码
## LOGGERS ##
#define a logger
#log4j.rootLogger=DEBUG,console,file
log4j.rootLogger=INFO,console,file
## APPENDERS ##
# define an appender named console, which is set to be a ConsoleAppender
log4j.appender.console=org.apache.log4j.ConsoleAppender
# define an appender named file, which is set to be a RollingFileAppender
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=e:/MyTrain/Java_Web_Frame/JavaLog/helloapp_log.txt
#set the log's size
log4j.appender.file.MaxFileSize=1000KB
log4j.appender.file.MaxBackupIndex=20
## LAYOUTS ##
# assign a SimpleLayout to console appender
log4j.appender.console.layout=org.apache.log4j.SimpleLayout
# assign a PatternLayout to file appender
log4j.appender.file.layout=org.apache.log4j.PatternLayout
# For debug
# log4j.appender.file.layout.ConversionPattern=[%-5p][%t][%C][%d{yyyy-MM-dd HH:mm:ss}] %m%n
# For deployment
log4j.appender.file.layout.ConversionPattern=[%-5p][%d{yyyy-MM-dd HH:mm:ss}] %m%n
