Servlet Primer
An implementation of recipe 2021-08-31 How to Start an HTTP Servlet
To see it in action, run ./gradlew clean appRun
Please change line httpPort = 9090
in build.gradle
if an Exception 'Failed to bind to /0.0.0.0:9090' is thrown.
In that case you may have to identify and kill Java process, left by Gretty plugin. It seems Gretty has no idea of a clean test ;)
Requires Java 8+, tested on Java 11