JDK 8 -> 9 migration was painful, but all other upgrades should be painless (well, maybe the 16-17, but I assume that most libraries will be fixed by the time y

JDK 8 -> 9 migration was painful, but all other upgrades should be painless (well, maybe the 16-17, but I assume that most libraries will be fixed by the time you upgrade - either add `add-opens` instructions or use appropriate new classes from JDK).