Place this two files in your classpath,
[commons-logging.properties]
org.apache.commons.logging.Log=org.apache.commons.logging.impl.SimpleLog
[simplelog.properties]
org.apache.commons.logging.simplelog.defaultlog=warn
#trace
#debug
#info
#warn
#error
#fatal
> whats about the output files ?
Decide where you want to put them. (Not inside the web application.) Configure the log4j.properties file so that the loggers write to where you decided. Put the log4j.properties file in your classpath. (The WEB-INF/classes directory is in your classpath.)