I've created a java-openjfx package (https://github.com/RaumZeit/PKGBUILDs/t ... va-openjfx) that compiles natively on ARM platform. It's tested with armv7h but should compile on armv8 and others as well.
For this PKGBUILD, I've taken the upstream ArchLinux PKGBUILD and added some patches required to circumvent cross-compilation on x86, which is the recommended way to produce ARM builds of OpenJFX. This procedure has been previously applied successfully for Debian, that's also where I took most of the patches from. I additionally added a patch that allows compilation/linking against ICU 59.1.
If this package is of interest for the ArchLinuxARM community, please feel free to merge my PR on github (https://github.com/archlinuxarm/PKGBUILDs/pull/1479). I'm also happy to incorporate any changes required for a successful merge into the official ArchLinuxARM PKGBUILDs repository.