Spring Boot is much more than just REST (or "microservices"), but consider Catalyst, e.g.

• Catalyst::Controller::REST
• Catalyst::Controller::DBIC::API::REST
• CatalystX::CRUD::REST

Update: On the other hand, Mojolicious has good support for REST out of the box.

E.g. Mojolicious::Routes::Route - get/post/put/delete/patch/options are all there. JSON is also supported, though not in the automatic way that Spring Boot can do.