Running your first JAX-RS 2.1 code

Jakarta RESTful Web Service, previously known as JAX-RS, is an API designed to give a portable and standard way of building RESTful web services in Java. This is one of the most widely used technologies for transporting data between different applications that use a network (the internet included) for communication.

One of the coolest features introduced by the 2.1 release is Server-Sent Events (SSE), which will be covered in this recipe. SSE is a specification created by HTML5, where it has established a channel between server and client, one way only from server to client. It is a protocol that transports a message containing some data.