Java with PLCNext engineer

Can you recommend tutorials or a manual on how to use Java with PLCNext engineer? I wrote a working program for Arduino that I’d like to convert to use Axo F 2152 but I assume I/O assignment is not the same and PLCNext engineer tutorials that I see rely on ladder logic. I can read and draw ladder wiring diagrams but never used ladder logic. I’d prefer to use my working written program.

The short answer is that PLCnext Engineer is currently not designed to use Java as a programming language. It only has support for POE’s written in the IEC 61131 languages, or C#, or C++.
However you can run Java applications on a PLCnext Control device, independently of the PLCnext Engineer project. There’s a Makers Blog article showing how you might be able to do this:
Java Application on PLCnext Control - PLCnext Community PLCnext Technology from Phoenix Contact is a unique, open ecosystem for modern automation that is capable of meeting all the challenges of the IoT world. The next step after that will depend on the application. If you want the Java application to directly access the I/O on the device, and if Java can use an ANSI-C interface, then you could create a „Runtime“-type application. If you want the Java application to access RSC Services in the PLCnext Runtime, then your application could implement a gRPC client. Neither of those solutions requires PLCnext Engineer.
For help with a specific application, the technical specialists in your local Phoenix Contact office will be able to help.