You need to create an AJAX client in your web-page. You could do this with a JavaScript timer that periodically requests data via a GET request to your application. Your application would need to listen for these requests using a TCP socket then respond.
Depending on the amount of data you are going to be sending back to the client you may want to consider changing the method to a POST instead of GET as GET is limited in the data response to the URL length.
You will also need to have a web-server, you could build a web-server into your application using TCP sockets, if not use Apache or something else for prototyping.
