In our company project we use LOG4j and it is very easy to use like Stephen showed in his example.
We also have written our own pattern classes for LOG4j so you can create your own output file schemas. You can describe how your log file should look like. It is possible to enhance the original log4j classes.
All LOG4j properties you can change in a log4j.properties file, so you can use different files for different projects.
Java logging is not my favorit, but this could be because i use log4j from the beginning.
