System development

Good morning everyone! It would not be to create a system, in fact I already have my whole system ready and quiet, what I'm wanting is a developer who has mastered the Java language, because my system it's all in Java. What I want is to implement Cappta's Tef API, which also has all of it ready and working and has already started the class that calls the CAPPTA TEF MODULE API, BUT IT IS INCOMPLETE, I HAVE ALL THE SOURCE CODE WHERE THE DEVELOPER WILL GO WORKING ON MY OWN MACHINE REMOTE AND HOW I KNOW THE CODE, I WILL SUPPORT INTERESTED DEVELOPER SHOWING SOME ROUTES OF THE SOURCE TO FACILITATE LITTLE LIFE OF THE DEVELOPER. So what I want is the following, as I already have all the code ready, the developer will continue this class already created, or create its own class he wishes, will call the API OF CAPPTA I HAVE READY, AND MAKE THE FLAME OF POS TO PROCESS THE MOVEMENT OF CREDIT CARD FOR SALE.