How to enable logging debug messages when root logger is INFO?

I use logger org.apache.commons.logging.Log.

File log4j.properties is:

log4j.rootCategory=INFO, S

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.logger.org.springsource.sawt=DEBUG
log4j.logger.org.w3c.tidy=INFO
...................

When I use debug method of org.apache.commons.logging.Log it doesn't log anything.

How to change log4j.properties to enable logger log debug messages?

Solution

It is really simple.

If you want to log all debug,info,warn.error,fatal messages from logger you need to take name of logger provided at instantiation by method LogFactory.getLog(loggerName) and append it to log4j.logger`. Thus you get

log4j.logger.loggerName=DEBUG

But it's common that loggerName is String from getClass() method. Thus you can use package name to set logger's level for that package.