Build with a different Java version (e.g. 11) using Docker

To spin up a temporary environment with a different Java version without touching your real environment, try this Docker command:

docker run -i -t --mount "type=bind,src=$PWD,dst=/code" openjdk:11-jdk bash

(Change "11-jdk" to the version you want as listed on the README.)

Then you can build the code inside the current directory something like this:

cd code
./gradlew test

Or similar for other build tools, although you may need to install them first.