Sun Java Instant Messaging Server and J2EE
By jhawk on Sep 25, 2007
The ServerSide has a great article on how to integrate "Presence" into your J2EE environment. This paper is a pretty good overview. Presence provides a mechanism for business applications to communicate the availability of users. The most obvious example is Internet Chat. You can see if someone is "offline", "online", or "busy." You could also extend this to write a phone switch, an escalation business workflow, or many other applications.
I would add to this paper that the Sun Java Instant Messaging Server provides the same XMPP functionality. The Sun Java Message Queue also provides the JMS functionality.
ServerSide Article "Integrating Presence in J2EE" by John Georgiadis