Declaring native functions to interface Java and C

I’m currently trying to get some information I’m getting from C functions back to the Java level of my application. I gather that I should use native functions to interface C to Java and have started looking into examples on how to use them, but I’m not sure where exactly I should declare my functions prior to using them in my code, is there any configuration files I should edit to declare functions that will interface Java and C ? And is there any specific naming convention I should respect when declaring them ?
Thank you for your time.

Hi Felix,

You can check this code samples on github:

Check also section 10.1 of the dev guide:
Kind regards,