The JBOSS server probably does not understand a redirect because it is not a browser.
Use encryption on the backend. In other words, accept the traffic as HTTP and forward it as HTTPS. You accomplish that by adding a serverssl profile to the virtual server accepting unencrypted traffic.
This also means that you will be using the same backend pool for both Virtual servers.
By the time you get the POST request, the POST data already traveled in the clear on its way to the BigIP. You may as well just forward it to the backend.