The latest version of The Well Grounded Java Developer was released in 2022, when 17 was the latest LTS version. The high quality of that book and being able to prescribe it is one reason why someone might prefer it.
I think OpenJDK 17 might also the highest LTS installable one on Debian 12 out of the box right now, but that's a lot less certain.
As far as I'm aware, the only officially supported way of shipping Java applications is by building custom runtimes with jlink. So if you want to play by the rules, it doesn't matter what the distributions ship.
Ubuntu ships multiple runtimes for every supported distribution and does backports FWIW.
`jlink` was released for Java 9, I believe, so it's unlikely people who are upgrading from Java 8 already have the infrastructure in place to seamlessly transition to that instead of however they were managing their JAR files before.
"But this should be simple! It's almost like a Go binary!" I've learned not to underestimate how long it can take to change infrastructure. DevOps isn't seen as a profit center in most places, and they might well have much bigger things to worry about than transitioning from a kind of working JARs-on-VMs approach.
Jlink/jpackage UX isnt the best either. They mostly produce installers not a single binary that you can just run. Project Leyden has some interesting work around this called Hermetic Java which plans to ship one binary with the VM + jar together. It’s coming out of some folks at Google. I’m really looking forward to it.
Really now? Now that's interesting. I thought GraalVM might be a good option in that space https://www.graalvm.org/ last I checked, but something literally called Hermetic Java has my interest piqued.
If you're using AWS ElasticBeanstalk Tomcat distribution, 21 isn't supported yet. I realize this isn't a huge segment of the market, but it's probably not the only example.
