Why use JAX-RS and WebSocket? Don't they serve the same purpose? Not exactly, in fact, it is becoming more and more common to use both in the same application even if WebSocket is still a bit recent.
JAX-RS (and, more generally, HTTP/1 and the brand new HTTP/2) is generally web application oriented. Understand that it is often used for applications with a user interface (which needs to be compatible with all browsers). It is also commonly used in environments where you cannot assume much about the network setup. More particularly, in environments where you cannot assume the network setup, the proxies will let WebSocket connections work properly (either preventing them completely or disconnecting them too early). The last ...
