Hai all godd evening. i need your help. i will explain the situation first. the application what i developing has only one ADMIN but there is no restrictions in the number of clients.
the problem is if the ADMIN user presses one button then somevalues must be updated in the database[that's not the problem i can manage to do it] then it should send a alert message to all the clients who are all using the application and there page must be updated according to the changes made in the database.
how can i do that? am still in the beginner level of the J2EE. so please help me to do it.
There is no way to push things to other clients using a web application because HTTP is a stateless protocol (meaning that users are only connected to the server long enough to draw each screen, then they disconnect).
While it's possible to have a web page should periodically if there are any updates (that's what AJAX does), it's not possible to push content out to pages that have been sent already.
Would it be sufficient to display the new values (or message or whatever it is) on the next page generated for those users? Then it would suffice to set a context attribute with the message, and have each request check that and display it if necessary.
[ UD: Pretty much the same as what Ben wrote, I see. ] [ January 21, 2008: Message edited by: Ulf Dittmer ]