public static String byte2hex(byte[] bytes) {
        StringBuilder hs = new StringBuilder();
        String stmp;
        for (int n = 0; bytes != null && n < bytes.length; n++) {
            stmp = Integer.toHexString(bytes[n] & 0XFF);
            if (stmp.length() == 1) {
                hs.append('0');
            }
            hs.append(stmp);
        }
        return hs.toString().toUpperCase();
    }
hex string to byte[], such as "0001" -> [0,1]

@param str hex string
@return byte[]
core/common/src/main/java/com/alipay/sofa/rpc/common/utils/CodecUtils.java