[1] JAX-RS uses annotations, introduced in Java SE 5, to simplify the development and deployment of web service clients and endpoints.
A notable feature of being an official part of Java EE is that no configuration is necessary to start using JAX-RS.
They include: In addition, it provides further annotations to method parameters to pull information out of the request.
The main targets are (among others) a common client API and support for Hypermedia following the HATEOAS-principle of REST.
Main new supported features include server-sent events, reactive clients, and JSON-B.