Back in early 2015, Oracle infamously removed JavaFX from its ARM JDK bundle and Java SE Embedded.
So we were pleasantly surprised to see Excelsior JET Embedded for Linux/ARM to pass our JavaFX tests.
Moreover, SWT tests passed too, so it seems you may be able to compile your graphical Java applications natively for ARM targets regardless of which of the major Java SE UI toolkits they use – AWT/Java2D/Swing, JavaFX, or SWT.
That said, there is no official support for JavaFX on ARM devices, so it may as well be broken on the particular piece of hardware that you are targeting. In fact, Oracle cited the abundance of non-standard hardware as the main reason for dropping support for JavaFX Embedded. We are unsure of the status of SWT support as well. So do extensive testing on you target device before committing to either technology.