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 enters an IP address like 173.194.36.37 application should display google.com and vice verse.

Are there any utilities available to perform this operation?

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);

Answer 2

What you're looking for is something called DNS. This project seems to be what you're looking for.

Answer 3

The project SomeKittens referred to you looks like a complete DNS server written in Java, which might be more than you need. Have a look at java.net.InetAddress:

java.net.InetAddress.getByName("example.com").getHostAddress();