Illegal base64 character a

            byte[] bytes = Base64Utils.decodeFromString(base64Str);
            byte[] bytes1 = new BASE64Decoder().decodeBuffer(base64Str);

    public static File base64StrToFile(String base64Str,String fileName,String parentPath){
        File file = new File(parentPath,fileName);
        FileOutputStream out = null;
        try {
            //byte[] bytes = Base64Utils.decodeFromString(base64Str);
            byte[] bytes1 = new BASE64Decoder().decodeBuffer(base64Str);
            ByteArrayInputStream in = new ByteArrayInputStream(bytes1);
            byte[] buffer = new byte[1024];
            out = new FileOutputStream(file);
            int byteSum = 0;
            int byteRead = 0;
            while ((byteRead = in.read(buffer)) != -1){
                byteSum += byteRead;
                out.write(buffer,0,byteRead);
            }
        }catch (Exception ex){
            throw new RuntimeException("transform base64 String into file 出错",ex);
        }finally {
            try {
                if(null != out){
                    out.close();
                }
            }catch (IOException ex){
                ex.printStackTrace();
            }
        }
        return file;
    }