IM status checker

[hisham.i]

Hello
I am developing Instant messaging application using java, i want to know how status checker algorithms work?.. I searched on google but i didn't get any useful link.
thanks

[chiro]

Hello
I am developing Instant messaging application using java, i want to know how status checker algorithms work?.. I searched on google but i didn't get any useful link.
thanks

What protocol and network do you want to use?

Maybe Trillian is a good place to start?

http://sourceforge.net/projects/trilldev/

[hisham.i]

Iam using tcp/ip...
What i was thinking about is to let the user listen in a specific port, and in order for another user to know that the first user is online, is to try to connect to him at that port if a socket is bounded then it is online if not then it is offline.

[chiro]

You will need to do something a bit more higher level.

The application protocol for IM will use something like a protocol in TCP/IP family.

My advice to you is to get some specific specs about a particular IM protocol and use that to do what you need to do.

What you're doing sounds like what typical port scanners do, but actually getting decent information from a client means you will need to do something more specialized.