IpTransformationsHelper

gistfile1.txt

/**
 *
 * @author enricodelzotto
 * @since 23/10/2017
 */
public class IpTransformationsHelper {
    /**
     * @param addr format xxx.xxx.xxx.xxx
     * @param mask string rapresentation of an int
     * @return
     */
    public static int convertIpToIntWithMask(String addr, String mask) {
        byte[] ipByts = new byte[4];
        String[] parts = addr.split("\\.");
        int ip = ((Integer.parseInt(parts[3]) << 24
                | Integer.parseInt(parts[2]) << 16
                | Integer.parseInt(parts[1]) << 8
                | Integer.parseInt(parts[1]) << 0)) & Integer.parseInt(mask, 16);
        return ip;
    }


    public static int converIpToInt(String addr) {
        String[] parts = addr.split("\\.");
        int ip = ((Integer.parseInt(parts[3]) << 24
                | Integer.parseInt(parts[2]) << 16
                | Integer.parseInt(parts[1]) << 8
                | Integer.parseInt(parts[1]) << 0));
        return ip;
    }


    /**
     * Return the String rapresentation of an inet IP from a integer
     *
     * @param i
     * @return
     */

    public static String intToIp(int i) {
        return ((i >> 24) & 0xFF) + "." +
                ((i >> 16) & 0xFF) + "." +
                ((i >> 8) & 0xFF) + "." +
                (i & 0xFF);
    }

    /**
     * Compare two different ip
     * @param ipOne
     * @param ipTwo
     * @param mask
     * @return
     */
    public static boolean areTheSameIpWithDifferentMask(String ipOne, String ipTwo, String mask) {
        return converIpToInt(ipOne) == convertIpToIntWithMask(ipTwo, mask);
    }
}