This is an example Play application that uses Java, and communicates with an in memory database using EBean.
The Github location for this project is:
https://github.com/playframework/play-ebean-example
Play documentation is here:
https://playframework.com/documentation/latest/Home
EBean is a Java ORM library that uses SQL:
https://www.playframework.com/documentation/2.5.x/JavaEbean
and
The Play HTML templates use the Play Bootstrap library:
https://github.com/adrianhurt/play-bootstrap
library to integrate Play with Bootstrap, the popular CSS Framework.