Download Java 17, Java Downloads.

HiDPI is automatically enabled on Windows. Not so on Linux, solution:
$ java -Dsun.java2d.uiScale=2.0 -jar ICrAData.jar
Only integer values accepted, still better than nothing.

Applying for app that uses Java2D:
$ export _JAVA_OPTIONS="-Dsun.java2d.uiScale=2.0"
$ myapp
Single command:
$ _JAVA_OPTIONS="-Dsun.java2d.uiScale=2.0" myapp

Applying for app that uses JavaFX, e.g. PDFsam, link:
$ export _JAVA_OPTIONS="-Dglass.gtk.uiScale=2.0"
$ pdfsam
Single command:
$ _JAVA_OPTIONS="-Dglass.gtk.uiScale=2.0" pdfsam

Verified for Debian/Devuan as of June 20, 2022.

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