A new feature in WebLogic 12c is the support for WebSockets. WebSockets are a server-side tech to allow push data to multiple client browsers with minimal overhead. They are useful when you want to provide real-time updates to users or want updates or content from one client to be pushed to multiple clients simultaneously. In the past (and on older browsers) you would have to use some form of long-polling (where the browser maintains an open connection with the server and sends messages back and forth on this single connection) to be able to provide these features. However, long-polling has a significant performance impact on your webserver as each connection must be kept open at all times (which does not scale well). With WebSockets you can avoid this performance impact and still deliver reliable instant communication with clients.
I’m not going to go into the detail of how WebSockets work (there are plenty of resources on the net for that), but in this post I will go through a simple example of WebSockets in WebLogic.