Recently I found that using Ubuntu 17.04 and Java 9 resulted in Java Swing based applications scaling correctly for my hdpi monitor. 17.04 and Java 8 did not scale correctly and this problem was fixed immediately when I updated Java.
This week I upgraded to 17.10 (which was necessary to resolve an unrelated problem with captured wifi hotspots).
Unfortunately, now Ubuntu 17.10 with Java 9 doesn't scale the Java Swing application anymore and I'm left to read tiny tiny writing again.
Does anyone know what went wrong and how to fix it?
The following bug page mentions a similar problem but seems to state that it was resolved, but without mentioning how: