How Client interact with Server in regular interval

Question

Hi friends,'
I want to develop a chat server where the user should sent the request to server in background(as server can not sent response unless the request appears).So on regular request from the Client the server check the updation in database and sent the correspong message to user.
How can i do this where the Client should interact with server in regular interval?
Is there any other way to accomplish this ,any reference guide /tutorial to develop this ?
Regards,
Sachin Warang.

Answer 1

You could add an <meta http-equiv="refresh" content="5;http://yourhost/context/servlet/"> to the HTML which will refresh the page every 5 seconds (change the 5 to 10 for every 10 seconds, etc.). The other way is to set up a JavaScript timer and use an XmlHttpRequest to make an asynchronous call to the server and update the HTML dynamically (using DOM) when a response is received (AJAX). Lastly, you could implement the client as an Applet, which gives you a much richer feature set and is a lot cleaner (having half of your app in JavaScript/DHTML is kind of messy).
There are some vendors, such as IceSoft (http://www.icesoft.com/) producing JSF components that do the AJAX stuff transparently, so you just code a normal JSF app using their components and wire up to bean action methods where you need to.
- Jesse