JNA is a simple jar library (google for videos of how to include jar libraries in your Eclipse project).
Honestly, you should avoid Eclipse. It's design is terrible and has been terrible for decades. Use NetBeans or IntelliJ Community: https://www.jetbrains.com/idea/download/
Both are free, both are worlds better than Eclipse.
But, yes, you can use TurboActivate with Eclipse. Google for tutorials on how to use jar libraries in your project, and include all of the *.java files in your project and you'll be good to go.