My book on Jakarta Commons is out very soon. It is called Jakarta Commons in Action and is being published by Manning.
The book contains detailed examples for most Commons components and provides extensive background information.
If you are interested, please send me an email with "Register for Commons Book" in the subject line, and I will let you know when it gets published. Also, Manning has an Early Access Program, which allows you to download the book contents as and when they become available. I will register you for that as well.
My Email address is: firstname.lastname@example.org