JAX-RS specification is a Java API for RESTful Web Services over the HTTP protocol. RESTEasy is a portable implementation of these specifications which can run in any Servlet container. RESTEasy also comes with additional features on top of plain JAX-RS functionalities.

A RESTFul application follows the REST architectural style, which is used for designing networked applications. RESTful applications generate HTTP requests performing CRUD (Create/Read/Update/Delete) operations on resources. RESTFul applications typically return data in JSON or XML format.

In our examples, we use Resteasy with Undertow server. We include Weld.