I tried both the latest alpn-boot jars from here: https://mvnrepository.com/artifact/org.mortbay.jetty.alpn/alpn-boot but it makes no difference, they don't even contain that class.
I'm using the Sun JDK.
Where do I find the correct jar?
Looks like this truly just doesn't work with the Oracle Sun JDK. It works with OpenJDK