To make WebLogic Server's log include messages from
Log4j and Commons Logging, insert log4WebLogic.jar
into the server's CLASSPATH, at the beginning.
Why is this useful? There are several
reasons. You can see the log messages even though you can't see
the server's System.out or System.err streams (as often happens in a
big server farm). You can see messages from all server software
modules in one time-sequenced log, which can help you understand what's
going on. You can use WebLogic tools to filter the log.
How does it work? Log4j reads log4j.properties, and consequently
Log4j routes messages to WebLogicAppender, which routes them to
WebLogic. You can interfere with this. For more
information, see log4j.properties and commons-logging.properties.