java code : byte[] -> Hex String

byte[] -> Hex String.md

    public static String bytesToHexString(byte[] bytes) {
        StringBuffer sb = new StringBuffer();
        for (byte b : bytes) {
            int val = b & 0xff;
            if (val < 0x10) {
                sb.append("0");
            }
            sb.append(Integer.toHexString(val));
        }
        return sb.toString();
    }