Integrating freecad with our java software

I want to integrate some 3D design software (opensource) with my java program. My requirement is that I should be able to design a parametric model (can be termed as master template file) with relationship. Eg: suppose I want to design a box of length x width x height 1. I make a new master template file. make 3d model of a box. I name length = L, width=L/2 and height=L/3 2. If I pass the value of L through my java program, the model should be updated automatically and I should get the updated drawing in my web browser (pdf or dxf would do) After lot of searching I found “freecad” which is based on python. I am still exploring its design capability. I need two help 1. If you know any other software please suggest or we work with freecad 2. A utility in java which would interact with freecad file. I send the parameter dimensions. The master template will get updated accordingly and would return the updated pdf or dxf let me know for more clarity Thanks & Regards, Pranav C Lunavat