Java - Getting a server's hostname and/or ip address from client

java sockets tcp hostname
Javier Pena picture Javier Pena · Nov 16, 2013 · Viewed 13.2k times · Source

So here is my situation. I need to use sockets in creating connections between server and client. This cannot be negotiated. I have a server running and listening using something like this

ServerSocket serverSocket = new ServerSocket(portNumber);
        while (listening) {
            new MultiClientThread(serverSocket.accept()).start();
        }

and I need a client to connect to the "portNumber" being listened to. The problem is I am using this line of code for the client.

Socket socket = new Socket(hostName, portNumber);

And I do not know how to get the "hostName" part for the parameters. Is it possible to get the "hostName" if I knew the portNumber that was being listened to? Or maybe another way to word it is how can I connect to a server listening to a port using tcp connections.

Answer

Femaref picture Femaref · Nov 16, 2013

hostName usually is hardcoded in the client. It can either be an ip address or a domain name. If the server is running the same machine, you can use localhost or 127.0.0.1 as hostname.

Related questions

Does a TCP socket connection have a "keep alive"?

I have heard of HTTP keep-alive but for now I want to open a socket connection with a remote server. Now will this socket connection remain open forever or is there a timeout limit associated with it similar to HTTP …

Read More
How to detect a remote side socket close?

How do you detect if Socket#close() has been called on a socket on the remote side?

Read More
how to achieve transfer file between client and server using java socket

I have implement the simple TCP server and TCP client classes which can send the message from client to server and the message will be converted to upper case on the server side, but how can I achieve transfer files …

Read More