converting an IP address to host name

Question

In my java application if user enters the IP we need to display the host name, if host name is given then we need to display the IP of the host.

For example if user

Answer 1

If you are coding in Java, try using InetAddress

InetAddress addr = InetAddress.getByName("173.194.36.37");
String host = addr.getHostName();
System.out.println(host);