You can use jfreechart http://www.jfree.org/jfreechart/ for creating charts and converting into diagrams.
If you want to use 3d charts probably you can try jzy3d.
Question
I have a programm that collects a lot of information and I want to export all this data in form of diagram and/or charts (as a pdf would be preference). What would be the method/libary of your choice to do so?
Solution
You can use jfreechart http://www.jfree.org/jfreechart/ for creating charts and converting into diagrams.
If you want to use 3d charts probably you can try jzy3d.