JFrame scaling in Java 9

Question

Exactly the same code running under Java 9u4 on the left and 8u144 on the right on Windows 7.

Java 9 seems to making the window larger. What is causing this

Answer 1

I found this obscure option in a substance bug report. This fixes the issue for Swing applications.

-Dsun.java2d.uiScale=1.0

If you're using JavaFX you'll need

-Dprism.allowhidpi=false

Unfortunately I cannot find official documentation for either of these options