c3p0 连接池的日志配置

如果用c3p0的话，经常会看到控制台上报一个警告，具体内容不急得了，大意是无法初始化MLog日志，请初始化log4j
出现此种情况是因为使用的c3p0这个连接池，并且没有正确配置其日志，只要把下面这段加到log4j.properties中即可

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#c3p0
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=OFF,A1
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=SEVERE,A1
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=WARNING,A1
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=INFO,A2
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=CONFIG,A2
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=FINE,A2
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=FINER,A2
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=FINEST,A2
log4j.category.com.mchange.v2.log.log4j.Log4jMLog=ALL,A2

#c3p0 appender
log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss,SSS} [%c]-[%p] %m%n
log4j.appender.A2=org.apache.log4j.RollingFileAppender
log4j.appender.A2.File=${sntweb.root}/logs/c3p0.log
log4j.appender.A2.MaxFileSize=500KB
log4j.appender.A2.MaxBackupIndex=1
#log4j.appender.A2.layout=org.apache.log4j.HTMLLayout
log4j.appender.A2.layout=org.apache.log4j.SimpleLayout