Logging with J2SDK 1.4 API or Log4J ?

According to this article:

After examining the standard logging API, my opinion is to stick with the log4j package if you are looking for a robust logging implementation. The logging API is adequate, but it is missing many of the features available in log4j. For instance, log4j already has a file rotation class that can rotate based upon the date. (You could extend the FileHandler class in the logging API, but why create more work for yourself?)

Read more in the article itself!