如何使用代理连接服务器？

Question

I made a server-client chat program in JAVA. Both client and server are running on the same machine. Now I want to use proxy server between them. eg; client connects to server via proxy, not by client's actual IP Address. I don't know if there is any library available to do this task or not. And I don't know which protocol should I use!!

//Client Class
Socket clientSocket = new Socket(InetAddress.getByName(ServerIP, 6789));

//Server Class
ServerSocket serverSocket = new ServerSocket(6789);
Socket socket = serverSocket.accept();

/********CONNECTION ESTABLISHED*******************************/

Now here I want to send connection request to server as a proxy instead of client IP Address on the same machine.

Answer 1

TCP sockets are low-level enough to not have any proxy mechanism on their own level. Higher-level protocols (HTTP, FTP etc) can be proxied easily, but TCP not.

However, you may look at SOCKS5 implementations. There is at least one implementation that can wrap unmodified TCP client application and route it via SOCKS5 proxy to unmodified TCP server application. I doubt this is the solution you're looking at, though.

TLDR: TCP connections can't be proxied using out of the box JDK APIs.