[Log4J|http://jakarta.apache.org/log4j/docs/index.html] is a nifty logging framework for Java applications.  Don't re-invent the wheel; give it a try. (Yes, it's supposedly better than 
the Java logging addition in JDK1.4.).

''As an endorsement I can say that JSPWiki uses Log4j for all of its logging needs :-) --JanneJalkanen''

BTW, you can use Jakarta commons-logging in order to plug in different logging frameworks, but IMHO just skip the extra level of indirection and use log4j directly.  --KenLiu