Get the RESTful Design Best Practices guide (choose your format). This guide reduces the world of RESTful services design into easy-to-follow principles. It also provides several cookbook type recipes in critical areas to increase service usability, reduce confusion during implemenation, as well as improve consistency.
RestExpress (GitHub). A lightweight microservices framework for Java, RestExpress composes best-of-breed tools to form a lightweight, minimalist Java framework for quickly creating RESTful APIs.