Intro

WebSockets is a technology that enables bidirectional communication between web browsers and server side processes. It provides a persistent connection between client & Server, hence enabling ‘push’ abilities where you can push data/notification to browsers from the client. Other client communication options to compare it with would be Ajax
and Comet (basically Ajax with long polling).

Specifications

• WebSockets API – This focuses on the client side programming model.
• WebSockets protocol – Describes the client/server communication in more detail. More complicated and 51 pages long. The WebSockets protocol is still actively being changed.

Browser Support

• Google Chrome 4.0.249.0 and higher (v5 has WebSockets enabled by default)
• Safari 5.0
• FireFox 4.0 beta 1
• IE 9: TBD

There was a suggestion that Apple have decided to disable WebSockets in iOS4 but this is unconfirmed and the speaker suspects Apple will support WebSockets in the future.

Server side support

• Apache Server – not supported yet
• Py WebSocket – designed for use with Apache Server (actually implemented by Google Chromium team.)
• There is also a DJango solution: django-websocket
• Jetty WebSocket Server – Jetty has supported WebSockets since last September. This seems to be a good option.

However, note that there is no standard service side Java API. Each Java container has it’s own API. Therefore it will likely be difficult to write WebSockets for one app server and do a straight port to another app server.

Projects

Other Java Projects supporting WebSockets:

• GlassFish/Grizzly (see a DZone posting on it here)
• jWebSocket
• JBoss Netty (see patch here)
• Caucho Resin

Sean finished by showing the Google Quake demo (also reported here).

The conclusion of the talk was on how to gracefully handle browsers that don’t support WebSockets (e.g. IE8). The main option here seems to be “The Graceful WebSocket“. This resorts back to using AJAX long pulling if WebSockets isn’t supported in the browser.

My Thoughts

WebSockets looks like one of the most interesting technologies that fall under the HTML5 umbrella. If it gets wide browser support (e.g. IE9), and perhaps some standardization on the server side, it could really take off and even potentially over take Ajax. Definitely one to watch…