16进制字符串转为16进制byte[]

java16进制字符串转为16进制byte[]

方法一

  /**
     * 16进制字符串转为16进制
     * @param hex 16进制的字符串
     * @return
     */
    public static byte[] hexString2Bytes(String hex) {
        if ((hex == null) || (hex.equals(""))){
            return null;
        }
        else if (hex.length()%2 != 0){
            return null;
        }
        else{
            hex = hex.toUpperCase();
            int len = hex.length()/2;
            byte[] b = new byte[len];
            char[] hc = hex.toCharArray();
            for (int i=0; i<len; i++){
                int p=2*i;
                b[i] = (byte) (charToByte(hc[p]) << 4 | charToByte(hc[p+1]));
            }
            return b;
        }
    }

方法二 

byte[] decodedHex = DatatypeConverter.parseHexBinary(str);