title: How to implement long polling in Java with Struts 2?
body: <p>I want to implement long polling in a java web application. Basically, when a user logs in, I want him to be hooked into a notification service. I want to push out new notifications to him from the server as they occur, and I want him to see those notifications in real time. ( so short polling or periodically checking with server from the client aren't good enough).</p>
  
  <p>How can I do this? Essentially, I want a way to push a string message from the server, and for the client to receive it immediately.</p>
  
  <p>I've heard some references that this could be done using a 'http chunk transfer' header from the server. But how would that be set up on the client?</p>