base64转换成字节流

public byte[] getBase614(String base614) {
        BASE64Decoder decoder = new BASE64Decoder();
        try {
            base614 = base614.substring(base614.indexOf(",", 1) + 1, base614.length());
            byte[] bytes = decoder.decodeBuffer(base614);
            for (int i = 0; i < bytes.length; ++i) {
                if (bytes[i] < 0) {// 调整异常数据
                    bytes[i] += 256;
                }
            }
            return bytes;
        } catch (Exception e) {
            System.out.println("io异常");
        }
        return null;
    }