Scale Java Applications for 4K displays

Java applications often don’t scale to higher resolutions (above Full-HD), making them barely readable on 4k resolutions. Generally, running an application with the additional JAVA-OPTS="-Dsun.java2d.uiScale=2" environment variable scales the application (here: at a factor of 2). Depending on how the application is launched, the steps on adding this variable are different.

On *.desktop launcher files

  1. Open the directory of the original *.desktop file.

  2. Create a copy of it, naming it something like <original_name>_4k.desktop.

  3. Open it in an editor and adjust the Exec= statement adding the needed environment variable. For example, change

    Exec=/usr/bin/flatpak run --branch=stable --arch=x86_64 --command=soapui-launcher.sh. org.soapui.SoapUI

    into

    Exec=env JAVA-OPTS="-Dsun.java2d.uiScale=2" /usr/bin/flatpak run --branch=stable --arch=x86_64 --command=soapui-launcher.sh. org.soapui.SoapUI

  4. Now run the new launcher file and the application should scale accordingly.