Topic awaiting preservation: updating website dynamically from server (java/php/ajax)

hello,

i want to connect a website to a javaprogram running on the server.
that is, if the javaprogram has something to say, all the users that are currently viewing a website are provided with that message.

how can i accomplish that? i can easily do a php-java-rmi bridge but how can i send the update to the client?

thanks!

Hm... I'd suggest ajax based polling to a php script that returns the output. You just regularly do a request, see if it has any message, if so, display the message.

ok, that might be an option. thanks!

but is there any way that the server notifies the website? i am asking, since the updates are coming very irregularly.

The issue is not with notifying the "website" but with notifying the visitors viewing the website. A user's web browser client connects to the website server, requests a document, then disconnects and shows the document to the user. While in this disconnected state, there is no way to PUSH information to the user. The user must PULL it from the website. That's where "polling" comes in. It can be done with AJAX as described. It could be done in Flash. It could be done with simple meta refresh timers. But one way or another, the user's client must initiate the conversation - the server cannot force the issue.

HTH,
- SK

thanks for the info!

i actually thought that this is the situation where AJAX comes in. i mean how does gmail-ajax-application get notified by the server when new mail arrives?

quote:

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i actually thought that this is the situation where AJAX comes in. i mean how does gmail-ajax-application get notified by the server when new mail arrives?

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Among the many Javascript processes that are running for Gmail is one that queries the server every minute or so to see if there's new mail to display. If there is new mail, the script refreshes the inbox and displays the new message. I suppose this could be AJAX, but I don't know if any XML is used.

-S

there is a technology called 'comet' that tries to achive what you want (keep connection open, the the webserver can 'push' data when/if it occurs).
But it's still in it's infancy as far as support and reliability is concerned, I believe.