Check whether the ipAddress is in private range

Question

How would I check to see whether the ip address is in private category ?

    if(isPrivateIPAddress(ipAddress)) {
                


        

Answer 1

I use this:

public boolean isPrivateIP(String ipAddress) {
        boolean isValid = false;

        if (ipAddress != null && !ipAddress.isEmpty()) {
            String[] ip = ipAddress.split("\\.");
            short[] ipNumber = new short[] { 
                    Short.parseShort(ip[0]), 
                    Short.parseShort(ip[1]), 
                    Short.parseShort(ip[2]),
                    Short.parseShort(ip[3])
                };

            if (ipNumber[0] == 10) { // Class A
                isValid = true;
            } else if (ipNumber[0] == 172 && (ipNumber[1] >= 16 && ipNumber[1] <= 31)) { // Class B
                isValid = true;
            } else if (ipNumber[0] == 192 && ipNumber[1] == 168) { // Class C
                isValid = true;
            }
        }

        return isValid;
    }