详解log4j.properties的简单配置和使用

### set log levels ### 
log4j.rootLogger = INFO , console , debug , error 
 
### console ### 
log4j.appender.console = org.apache.log4j.ConsoleAppender 
log4j.appender.console.Target = System.out 
log4j.appender.console.layout = org.apache.log4j.PatternLayout 
log4j.appender.console.layout.ConversionPattern = %-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n 
 
### log file ### 
log4j.appender.debug = org.apache.log4j.DailyRollingFileAppender 
log4j.appender.debug.File = ../logs/springmvc-demo.log 
log4j.appender.debug.Append = true 
log4j.appender.debug.Threshold = INFO 
log4j.appender.debug.layout = org.apache.log4j.PatternLayout 
log4j.appender.debug.layout.ConversionPattern = %-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n 
 
### exception ### 
log4j.appender.error = org.apache.log4j.DailyRollingFileAppender 
log4j.appender.error.File = ../logs/springmvc-demo_error.log 
log4j.appender.error.Append = true 
log4j.appender.error.Threshold = ERROR 
log4j.appender.error.layout = org.apache.log4j.PatternLayout 
log4j.appender.error.layout.ConversionPattern = %-d{yyyy-MM-dd HH\:mm\:ss} [%p]-[%c] %m%n 
 
 
###需要声明，然后下方才可以使druid sql输出，否则会抛出log4j.error.key not found 
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{ISO8601} %l %c%n%p: %m%n 
 
### druid sql ### 
log4j.logger.druid.sql=warn,stdout 
log4j.logger.druid.sql.DataSource=warn,stdout 
log4j.logger.druid.sql.Connection=warn,stdout 
log4j.logger.druid.sql.Statement=warn,stdout 
log4j.logger.druid.sql.ResultSet=warn,stdout 

 public Test{
  Logger log = Logger.getLogger(Test.class)//log.info() 调用  
 }

log4j.appender.appenderName = fully.qualified.name.of.appender.class

log4j.appender.appenderName.option1 = value1

…

log4j.appender.appenderName.optionN = valueN

log4j.appender.appenderName.layout = fully.qualified.name.of.layout.class

log4j.appender.appenderName.layout.option1 = value1

…

log4j.appender.appenderName.layout.optionN = valueN