Java tutorial
import java.net.InetAddress; public class Main { public static void main(String[] argv) throws Exception { InetAddress addr = InetAddress.getByName("127.0.0.1"); byte[] ipAddr = new byte[] { 127, 0, 0, 1 }; addr = InetAddress.getByAddress(ipAddr); // Get the host name String hostname = addr.getHostName(); // Get canonical host name String canonicalhostname = addr.getCanonicalHostName(); } }