In my development career I have found REST-ful resources to be a desirable path. SOAP XML is heavy and at times overly complex, albeit very useful and probably will never go away.
That said, I have generally used Spring MVC for my RESTful resource implementations. This blog link demonstrates creating them with using the “Spark” Framework. I’ve never used Spark but these examples make creating REST-ful resources look really easy: REST with Java 8, Maven, and Spark – via @DZone
This is a sibling blog discussing “RESTful API Authentication Basics”
And keeping with Spring MVC Theme I found this REST Controller tutorial that is a decent read to get you going: Spring MVC 4 RESTFul Web Services CRUD Example+RestTemplate
Enjoy! And happy coding!