This is my main training ground of creating a fullstack java spring-driven application. Its' core was modeled after this youtube course: https://www.youtube.com/playlist?list=PL9l1zUfnZkZkmDvzHCoLlc_nHBc7ZXiRO. The frontend part is based on NiceAdmin template: https://bootstrapmade.com/nice-admin-bootstrap-admin-html-template/. It is an admin page with fully functioning connection to MySQL DB and a login system.
To use the template, simply clone it and change credentials in application.properties to match your local MySQL Server's. Spring Data library will create full_java_app database and its' tables automatically on the first launch.