public static byte[] convertFromIPv4MappedAddress(byte[] addr) 
{
        if (isIPv4MappedAddress(addr)) {
            byte[] newAddr = new byte[INADDR4SZ];
            System.arraycopy(addr, 12, newAddr, 0, INADDR4SZ);
            return newAddr;
        }
        return null;
}

 public static boolean isIPv4LiteralAddress(String src) 
{
        return textToNumericFormatV4(src) != null;
}

 public static boolean isIPv6LiteralAddress(String src) 
{
        return textToNumericFormatV6(src) != null;
}

 public static byte[] textToNumericFormatV4(String src) 
{
        if (src.length() == 0) {
            return null;
        }
        byte[] res = new byte[INADDR4SZ];
        String[] s = src.split("\\.", -1);
        long val;
        try {
            switch(s.length) {
            case 1:
                /*
                 * When only one part is given, the value is stored directly in
                 * the network address without any byte rearrangement.
                 */
                val = Long.parseLong(s[0]);
                if (val <  0 || val  > 0xffffffffL)
                    return null;
                res[0] = (byte) ((val  > > 24) & 0xff);
                res[1] = (byte) (((val & 0xffffff)  > > 16) & 0xff);
                res[2] = (byte) (((val & 0xffff)  > > 8) & 0xff);
                res[3] = (byte) (val & 0xff);
                break;
            case 2:
                /*
                 * When a two part address is supplied, the last part is
                 * interpreted as a 24-bit quantity and placed in the right
                 * most three bytes of the network address. This makes the
                 * two part address format convenient for specifying Class A
                 * network addresses as net.host.
                 */
                val = Integer.parseInt(s[0]);
                if (val <  0 || val  > 0xff)
                    return null;
                res[0] = (byte) (val & 0xff);
                val = Integer.parseInt(s[1]);
                if (val <  0 || val  > 0xffffff)
                    return null;
                res[1] = (byte) ((val  > > 16) & 0xff);
                res[2] = (byte) (((val & 0xffff)  > > 8) &0xff);
                res[3] = (byte) (val & 0xff);
                break;
            case 3:
                /*
                 * When a three part address is specified, the last part is
                 * interpreted as a 16-bit quantity and placed in the right
                 * most two bytes of the network address. This makes the
                 * three part address format convenient for specifying
                 * Class B net- work addresses as 128.net.host.
                 */
                for (int i = 0; i <  2; i++) {
                    val = Integer.parseInt(s[i]);
                    if (val <  0 || val  > 0xff)
                        return null;
                    res[i] = (byte) (val & 0xff);
                }
                val = Integer.parseInt(s[2]);
                if (val <  0 || val  > 0xffff)
                    return null;
                res[2] = (byte) ((val  > > 8) & 0xff);
                res[3] = (byte) (val & 0xff);
                break;
            case 4:
                /*
                 * When four parts are specified, each is interpreted as a
                 * byte of data and assigned, from left to right, to the
                 * four bytes of an IPv4 address.
                 */
                for (int i = 0; i <  4; i++) {
                    val = Integer.parseInt(s[i]);
                    if (val <  0 || val  > 0xff)
                        return null;
                    res[i] = (byte) (val & 0xff);
                }
                break;
            default:
                return null;
            }
        } catch(NumberFormatException e) {
            return null;
        }
        return res;
}

 public static byte[] textToNumericFormatV6(String src) 
{
        // Shortest valid string is "::", hence at least 2 chars
        if (src.length() <  2) {
            return null;
        }
        int colonp;
        char ch;
        boolean saw_xdigit;
        int val;
        char[] srcb = src.toCharArray();
        byte[] dst = new byte[INADDR16SZ];
        int srcb_length = srcb.length;
        int pc = src.indexOf ("%");
        if (pc == srcb_length -1) {
            return null;
        }
        if (pc != -1) {
            srcb_length = pc;
        }
        colonp = -1;
        int i = 0, j = 0;
        /* Leading :: requires some special handling. */
        if (srcb[i] == ':')
            if (srcb[++i] != ':')
                return null;
        int curtok = i;
        saw_xdigit = false;
        val = 0;
        while (i <  srcb_length) {
            ch = srcb[i++];
            int chval = Character.digit(ch, 16);
            if (chval != -1) {
                val < < = 4;
                val |= chval;
                if (val  > 0xffff)
                    return null;
                saw_xdigit = true;
                continue;
            }
            if (ch == ':') {
                curtok = i;
                if (!saw_xdigit) {
                    if (colonp != -1)
                        return null;
                    colonp = j;
                    continue;
                } else if (i == srcb_length) {
                    return null;
                }
                if (j + INT16SZ  > INADDR16SZ)
                    return null;
                dst[j++] = (byte) ((val  > > 8) & 0xff);
                dst[j++] = (byte) (val & 0xff);
                saw_xdigit = false;
                val = 0;
                continue;
            }
            if (ch == '.' && ((j + INADDR4SZ) < = INADDR16SZ)) {
                String ia4 = src.substring(curtok, srcb_length);
                /* check this IPv4 address has 3 dots, ie. A.B.C.D */
                int dot_count = 0, index=0;
                while ((index = ia4.indexOf ('.', index)) != -1) {
                    dot_count ++;
                    index ++;
                }
                if (dot_count != 3) {
                    return null;
                }
                byte[] v4addr = textToNumericFormatV4(ia4);
                if (v4addr == null) {
                    return null;
                }
                for (int k = 0; k <  INADDR4SZ; k++) {
                    dst[j++] = v4addr[k];
                }
                saw_xdigit = false;
                break;  /* '\0' was seen by inet_pton4(). */
            }
            return null;
        }
        if (saw_xdigit) {
            if (j + INT16SZ  > INADDR16SZ)
                return null;
            dst[j++] = (byte) ((val  > > 8) & 0xff);
            dst[j++] = (byte) (val & 0xff);
        }
        if (colonp != -1) {
            int n = j - colonp;
            if (j == INADDR16SZ)
                return null;
            for (i = 1; i < = n; i++) {
                dst[INADDR16SZ - i] = dst[colonp + n - i];
                dst[colonp + n - i] = 0;
            }
            j = INADDR16SZ;
        }
        if (j != INADDR16SZ)
            return null;
        byte[] newdst = convertFromIPv4MappedAddress(dst);
        if (newdst != null) {
            return newdst;
        } else {
            return dst;
        }
}