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();
}
}