Here are some little pieces of Java software you might find useful. They were invented along the way to doing other things, and got re-used enough to suggest you might get some benefit from them. Enjoy!

Nugget
encoding	Encode data using streams. Includes an implementation of Base64 encoding.
io	Input/Output utilities.
log4WebLogic	Route log messages from Log4j and Commons Logging into a WebLogic Server log.