Oh, look, there's already an antique jre installed on my os, not compatible with the particular jre needed by this application, which I first need to uninstall. And then hope that it doesn't break anything else in the process, because I haven't been following the minutae of java development environments for the last n+1 years...
I think it falls solidly in the "easy if you know it, and a wasted q hours if you don't" category.
Just download it, copy it and set JAVA_HOME to make it easier for other applications.
I've done this on hundreds of servers during my lifetime and never once had an issue.