Chapter 17. WebSockets

The WebSocket protocol provides two way communication between web clients and servers. Communications between clients and the server are event-based, allowing for faster processing and smaller bandwidth compared with polling-based methods. WebSocket is available for use in web applications via a JavaScript API.

A connection is first established between client and server as an HTTP connection. The client then requests a WebSocket connection using the Upgrade header. All communications are then full-duplex over the same TCP/IP connection, with minimal data overhead. Because each message does not include unnecessary HTTP header content, Websocket communications require smaller bandwidth. The result is a low latency communications path, suited to applications which require real-time responsiveness.

The JBoss EAP 6 WebSocket implementation provides full dependency injection support for server endpoints, however, it does not provide CDI services for client endpoints. CDI support is limited to that required by the Java EE 6 platform, and as a result, Java EE 7 features such as interceptors on endpoints are not supported.