I had to containerize an older java app. It sucked, java would take all the memory you gave it regardless, so it was hard to determine memory requirements/limits. It had pretty slow start although this wasn't an issue for us, logging formatting was a pain. All this was overcome (not by upgrading), it was just a pain.
I suspect this isn't true of modern java though - I'd suspect with the hype kubernetes went through a few years ago that it's just fine now a days.