Question

How to convert decimal presentation of an ip address to 32bit integer value in java?
I use InetAddress class and getLocalHost method to obtain an IP adress:

public class getIp {

public static void main(String[] args) {
   InetAddress ipaddress;

    try {
      ipaddress=InetAddress.getLocalHost();
       System.out.println(ipaddress);
        }
      catch(UnknownHostException ex)
      {
        System.out.println(ex.toString()); 
      }


    }
}

Than I should convert the result to 32bit integer value and than to string, how do I do that?
Thanks!

Answer 1

If the IP address is IPv6, it won’t work.
Otherwise for the Sun/Oracle implementation and IPv4, you can play dirty:
ipaddress.hashCode()—works but may break in the future, therefore not recommended.

Otherwise (recommended): int ipv4 = ByteBuffer.wrap(addr.getAddress()).getInt()