At the very beggining of my work with Java i had problems with many document generation systems and at that time I wasn't succesfull.
One day my searching was finished!
My business developed since that times but I'm still a proud user of http://<a href="http://http://www.ja...generation</a>]
If you are looking for a document generation system on Java, take a look at this http://<a href="http://http://www.ja...generation</a>] site. It has basic info on all the vendors. It makes for a great starting point.