Well, I can add 2 more names to that list to check out: DataVision
Those are 2 java-based reporting frameworks. I was looking into them when I was trying to do exactly what you are attempting, but to incorporate it into Tomcat. For my purpose, I just ended up creating a jsp page that generated a specific report page and gave the users a print button at the top of that page that wouldn't show up on the resulting printed report.
IIRC, DataVision showed the most promise for allowing the end-user to access and generate whatever reports they wanted/needed, but lack of activity at sourceforge might be a sticking point.