NFe software in java [closed]

I have a project to create an NFe emitter in Java ... But the problem is that I do not have much idea and much knowledge for the development of this type of project.
Anyone know if you have any library, paid or free, to develop an NFe emitter in java?
I found this project: link
I would like to know if anyone has ever used or tested .. Or better to do everything in hand, from scratch?
I need to have an idea about this, if anyone can help me, indicate some tutorial or some library ... I need to develop for the Web.