Java APIs

Hello,
I recently developed and application based on TCP/IP Socket in Java (some kind of chat). Everything is working fine on LAN but the connection is refuzed when I use public IP addresses and I need my application to work on internet not LAN. I tried to stop all firewalls... same thing. I pinged my public IP address.. same thing. I could make it work just by forwarding the port with my router BUT I don't want to do this. I want any client anywhere to connect to the other application. So I need to entablish a connection between them. Is HTTP tunneling good for this? If so, how can I implement it? I think I need some kind of VPN or something. The port is close on the public IP on the server so the client gets refused connection from the server.

So how can I entablish the connection between the two sockets on internet? (without any router forwarding stuff)

Thanks.