任何协议的简单正向代理

Question

I am wanting to develop a centralized java server that accepts multiple connections for any type of network traffic IE FTP, HTTP, HTTPS, RDP, etc. The only goal is to forward it off to the expected destination and return the response back to the requester. I have no idea where to start with this because the only information I am finding is related to forwarding java servlet requests and some info on forwarding HTTP. Is there anyway to simply forward it off, or would it require handling every protocol differently?

public void run () {
    InetSocketAddress address = (InetSocketAddress)this.socket.getRemoteSocketAddress();
    try {
        InputStreamReader isr = new InputStreamReader(this.socket.getInputStream());
        BufferedReader br = new BufferedReader(isr);
        OutputStream os = this.socket.getOutputStream();
        String ipAddress = address.getHostName();
        Log.d("client","A client has connected from: "+ipAddress);

        //TODO forward the client inputstream to the destination

    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        try{
            this.socket.close();
        } catch (Exception e) {}
    }
}

Answer 1

Every protocol is different, unless you want to, and can, force them all into one straightjacket like HTTP's CONNECT verb. You will have to research what proxy protocols the intended clients are capable of using.

More probably you should be looking at using SOCKS, in an existing implementation.