I'm not 100% sure of what I'm saying as I don't have the means to test it right now, so take it with a grain of salt.
You're listening to 127.0.0.1, which corresponds to InternetAddress.LOOPBACK_IP_V4, and I think it can only be reached from clients running on the same machine.
Have you tried running the server on InternetAddress.ANY_IP_V4?