Trigger a web page refresh

I am working on an android application that will show an html page that contains only some text on a table开发者_如何学Got device. The device will be on and showing this page for long periods of time(several hours). The text on this page will get changed from time to time.

To change the text on the page I've made a separate second page that contains a form to enter the new strings into and a submit button that uses ASP to generate a new version of the first page and save it over top of the original copy. This is set up and working great, but it means that I have to refresh the page very frequently in order to ensure I am always showing the latest message.

I am looking for a way that I could trigger a refresh only when a new message is saved. That way I will not have to refresh the page every minute but the new message will still get shown in a timely manner.

No dice, HTTP is built as a stateless, pull-only (ignoring file uploads) protocol. The server can't push data to the client, the client has to actually poll the server for new information.

However, you can minimize the overhead of this by using an AJAX call with JSON as the transport protocol instead of generating entire web pages and update your page on the client side. The overhead should be minimal for almost any application.

If you were just a web-app, I would suggest looking into the various Comet frameworks.

http://www.google.com/search?q=comet+framework

But, since you have an Android shell around it, you can make a Socket connection back to your server and have the server signal when it's time to refresh. It's essentially the same, but you don't need to code up the push in JavaScript if you're more comfortable in Java.