Server-Sent Events

Server-Sent Events (SSE) is a standard and part of HTML 5; it allows for one-way communication from the server to the client. So, a client can make one request and the server can keep sending multiple responses on the same connection. The client opens the connection with a server by passing the Accept header as text/event-stream. This connection is a long-running one between the client and server. The server can then publish events over the HTTP protocol. This allows for a better solution for pushing updates to clients than clients having to resort to inefficient means such as polling. JAXRS 2.1 has made API enhancements to support SSE. On the server-side, we can define a resource that produces text/event-stream, which clients can register with to receive events. Let's look at an example, where we combine CDI and JAXRS to push task updates to the interested...