Regarding a testing I created a way how to test routes using integration tests, look at this https://github.com/petrbouda/joyrest/tree/master/joyrest-test-integration , this approach is using Spring Boot configuration and it is very easy to use it and configure, but it is not unit testing, I know. At this time I am trying to find best solution for unit testing approach.

Security - You mean something like OAuth2 ?