下载oss到本地,文件内容是空白的无法渲染

打包下载oss文件,下载到本地解压缩后,打开查看里面是空白的,有一页是现实无法渲染该页面

相关代码如下

 String url;
        // 多个文件集合
        ArrayList files = new ArrayList<>();
        // 根据signId查询签署文档
        List signDocumentVOS = signDocumentMapper.selectAttachs(signId);
        for (SignDocumentVO signDocumentVO : signDocumentVOS) {
            url=signDocumentVO.getLink();
            files.add(url);
        }
        // 配置文件下载
        response.setCharacterEncoding("utf-8");
        response.setContentType("application/file");
        //压缩包文件名
        SimpleDateFormat fileZipName = new SimpleDateFormat("yyyyMMddhhmmss");
        // 下载文件时候防止显示中文乱码 指定文件类型 .zip
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileZipName.format(new Date()) + ".zip", "UTF-8"));
        response.flushBuffer();
        ZipUtils.getZipFile(IOUtils.getByte(files), response.getOutputStream(),response);

  public static void getZipFile(Mapbyte[]> stringByte, OutputStream outputStream, HttpServletResponse response) throws Exception {
        //将文件打包成压缩文件
        ZipOutputStream zipout = new ZipOutputStream(outputStream);
        Set[]>> dataEntrys = stringByte.entrySet();
        for (Map.Entry[]> data : dataEntrys) {
            InputStream bufferIn = new BufferedInputStream(new ByteArrayInputStream(data.getValue()));
            byte[] bs = new byte[1024];
            Arrays.fill(bs, (byte) 0);
            //创建压缩文件内的文件
            zipout.putNextEntry(new ZipEntry(data.getKey()));
            int len = 0;
            while ((len = bufferIn.read(bs)) > 0) {
                zipout.write(bs, 0, len);
                zipout.flush();
            }
            response.flushBuffer();
            bufferIn.close();
        }
        try {
            zipout.close();
            outputStream.flush();
        } catch (IOException e) {
        }
    }