How can I tell Xwiki to use Java 1.8?

Hi, I need Java 12 for work, but as we already know, Xwiki does not run on any other version than 1.8. I have installed java-1.8.0-openjdk-amd64, now, how can I tell xwiki to use this version? Still, when I run start_xwiki.sh it says, that I have java 12 and it is not supported.

Hi. You could try https://dev.xwiki.org/xwiki/bin/view/ReleasePlans/ReleasePlanHelp#HConfiguretheJavaVersion

Actually XWiki 11.x is supposed to work fine on Java 11+.