How can I protect Java/Javafx code from being seen by final user?

Question

I have been working on a project alone for more than two years for a company. The project is a really big one using rxtx to communicate with a hardware device. I used Java 8

Answer 1

I currently work for a company that has code that we don't want anyone to have access to for the security of our clients and-- less important-- for legal reasons. ;-)

One possible solution you could look into would be to rewrite the code you deem most sensitive into a C/C++ library. It would be possible to compile this into a .so/.dll/.dylib file for the respective OSs and it would make it difficult, not entirely impossible, but difficult to decompile.

The trouble would come from learning how to access native code from Java as much of the documentation is not helpful or just simply nonexistent. This would utilize the Java Native Interface (JNI) which allows Java to, well, interface with the native (compiled C/C++) code. This would make it possible to create a Jar file that would effectively become a Java library for you to access throughout the rest of your project. The native code, however will still need to be loaded at runtime, but that's apart of learning how JNI works. A helpful link I found for JNI is http://jnicookbook.owsiak.org/ (for as long as it's still a functional link).

One of our clients here where I work has a project written in Java and needed to implement our code that is unfortunately all written in C. So we needed a way to access this C/C++ code from Java. This is the way we went about solving this issue without rewriting our code in Java. But we had the benefit (?) of having already written our code in C.

This solution to write a bunch of extra code last minute in another language that I may or may not be familiar with doesn't sound like particularly fun time.

I would be curious to learn what possible problems others might see with this solution.