Re: Sending Response Objet to client without request.

[APL]

Your question raises some interesting issues about the limitations of the web server-client relationship. Ideally, what you need is a classic "publish and subscribe" paradigm (which is what this servlet mailing list  is really, except its using email), but this isn't how web clients and their hosts work together - its more like "ask me a question, and I'll (try to) tell you the answer, but if I don't find it till later, you'll never know!!", which is hardly a satisfactory solution, if one at all, but hey, it cheap and easy to develop and deploy! An alternative is to have a special network listener (a web server is a glorified listener, but one that only operates "on demand") that maintains continuous communication with its clients, even when there's nothing to "say", which is expensive on network resources, so there's the downside, but doable. Maybe you need to think instead about EJB's and RMI (since Java doesn't support the function pointers that would allow a callback function between (say) a C++ client and an RPC to a remote host)...good luck! -----Original Message----- From: A mailing list for discussion about Sun Microsystem's Java Servlet API Technology. [mailto:[EMAIL PROTECTED]]On Behalf Of Mike Silvers Sent: 24 October 2002 12:24 To: [EMAIL PROTECTED] Subject: Re: Sending Response Objet to client without request. HTML is the result of a request to the server, and after the response is sent from the server, the server has no idea that the client is there until it receives another request.  You could have the page refresh every xx seconds, but this would cause a big overhead for the server.  You could also do this using applets -- the server can communicate with the applet sessions.  Most HTML based chat programs work with applets for this reason.   Mike   ----- Original Message ----- From: Galbreath, Mark To: [EMAIL PROTECTED] Sent: Thursday, October 24, 2002 7:15 AM Subject: Re: Sending Response Objet to client without request. Not with HTTP. -----Original Message----- From: Mazhar@grouppk [mailto:[EMAIL PROTECTED]] Sent: Thursday, October 24, 2002 1:07 AM To: [EMAIL PROTECTED] Subject: Sending Response Objet to client without request. hi;   I have to develop an application that have to fetch data from server after some time, or when ever there are some changes in data on the server then server have to send those changes to the clients ( http clients viewing that site). The simplest way to set some time interval in java script of client side to refresh the page.   Is there any way that I can send response to all clients without their request ( I have IPs of those clients)..????   Any Comments or suggestions...   Mazhar!