The class java.net.InetAddress represents an Internet Protocol (IP) address. You can use this class to find the hostname of an IP address. The following code demonstrates this:
try{ java.net.InetAddress inetAdd =java.net.InetAddress.getByName("127.0.0.1"); //127.0.0.1 is loop back address System.out.println ("Hostname is: " + inetAdd.getHostName());}catch(catch(java.net.UnknownHostException uhe){ //handle exception}