GridFs文件下载

 public Boolean downloadFile(String id, String name, HttpServletRequest request, HttpServletResponse response){
        //根据ID查询文件是否存在
        FileUpload upload = gridFSUploadDao.findOne(id);
        if(CommentUtils.isEmpty(upload)){
            throw new BadRequestException(ExceptionEnum.FILE_NOT_FOUND.getMessage());
        }
        //将下载操作记录至文件下载表中
        FileDownload download = new FileDownload();
        download.setCreateTime(DateUtils.dateToISODate(new Date()));
        download.setUpdateTime(DateUtils.dateToISODate(new Date()));
        download.setFileName(upload.getFileName());
        download.setFileId(upload.getGridId());
        download.setOperator(name);
        download.setDelete(false);

        gridFSDownloadDao.insertDownload(download);

        Query query = Query.query(Criteria.where("_id").is(upload.getGridId()));
        byte[] resource = GridFsUtils.downloadFile(mongoTemplate,gridFsTemplate,query);
        byte[] buffer = new byte[1024];
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(resource);
        try {
            OutputStream out = response.getOutputStream();
            int i = byteArrayInputStream.read(buffer);
            while (i != -1) {
                out.write(buffer, 0, i);
                i = byteArrayInputStream.read(buffer);
            }
            out.flush();
            System.out.println("********************下载success**************");
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if (byteArrayInputStream != null) {
                try {
                    byteArrayInputStream.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }






//        OutputStream os = null;
//        InputStream is= null;
//        try {
//            // 取得输出流
//            os = response.getOutputStream();
//            // 清空输出流
//            response.reset();
//            response.setContentType("multipart/form-data");
//            response.setHeader("Content-Disposition", "attachment;filename="+ new String(upload.getFileName().getBytes("utf-8"), "iso-8859-1"));
//            response.addHeader("Content-Length", "" + upload.getFileSize());
//            is = resource.getInputStream();
//            //复制
//            IOUtils.copy(is, response.getOutputStream());
//            response.getOutputStream().flush();
//            log.info("********************下载success**************");
//        } catch (Exception e) {
//            throw new BadRequestException(e.getMessage());
//
//        }finally {
//            try {
//                if (is != null) {
//                    is.close();
//                }
//            } catch (IOException e) {
//                log.error(ExceptionUtils.getFullStackTrace(e));
//            }
//            try {
//                if (os != null) {
//                    os.close();
//                }
//            } catch (IOException e) {
//                log.error(ExceptionUtils.getFullStackTrace(e));
//            }
//        }
        return true;
    }