Good news from EE 7! JSON is included in the specification. HTTP always becomes more default, not only for writing web applications but also for services! REST through JSON confirms the HTML 5 approach and becomes the guideline for not only the frontend but also the service tier.
Undertow is the new substitute for Tomcat, becoming not only a servlet container but the infrastructure that manages all Java EE 7 web technologies as JSON, REST, and WebSockets.