IntelliJ highlights the getFirstName method as it is wrong. However, everything works and compiles. What can I do to make Maven see this method as well?
If everything works and compiles it might not be from Maven. Sometimes IntelliJ gets confused. If you haven't done this I'd suggest you to File | Invalidate Caches/Restart
Hope it helps.
Edit : As Petr Aleksandrov commented, you can check the Jidea Annotation processor : Configuring Annotation Processing