网上找了很多关于 slf4j配置文件，都是说与log4j的一样，
log4.properties
#log4j.rootLogger = [ level ] , appenderName, appenderName, ...
log4j.debug=true
log4j.rootLogger = INFO, console, R
#level=INFO,all can be output
#console is set to be a ConsoleAppender
log4j.appender.console = org.apache.log4j.ConsoleAppender
#console have four patterns
#org.apache.log4j.HTMLLayout
#org.apache.log4j.PatternLayout
#org.apache.log4j.SimpleLayout
#org.apache.log4j.TTCCLayout
log4j.appender.console.layout = org.apache.log4j.PatternLayout
#define the output type
log4j.appender.console.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] %m%n
#file is set to output to a extra file
log4j.appender.R = org.apache.log4j.RollingFileAppender
#the absolute route of the log4j file
log4j.appender.R.File = /log.txt
#the size
log4j.appender.R.MaxFileSize = 500KB
#back up a file
log4j.appender.R.MaxBackupIndex = 1
log4j.appender.R.layout = org.apache.log4j.PatternLayout
log4j.appender.R.layout.ConversionPattern=%-d{yyyy-MM-dd HH:mm:ss} [%c]-[%p] - %m%n
这个文件在log4j下可以正常运行，可是换成slf4j的就不起作用了，
这是怎么回事呀
说明：肯定不是包冲突了，我都试过了，
