There's a few problems with that:
First, DNS cannot include port numbers.
Second, DNS cannot include a path.
Third, the maximum port number is 65535, so even if DNS did let you add a port number, that port number is too high.
You'll probably want to just send your domain directly to the server. Use apache to reverse proxy 80/443 to 8080/8009 (glassfish default ports for http/ajp), and just add a mod_rewrite rule that redirects /
to /my-app
.