求助： springmvc 上传至 mongodb 后下载文件无法打开

Question

使用SpringMVC + mongodb 做文件的上传和下载，
下载的文件除TXT（乱码）外均无法打开。

1.怀疑是springmvc messageconverter配置的问题，尝试配置了byteArrayConverter
2.怀疑是上传存储到mongodb时文件损坏，谷歌和百度均未找到相关内容
3.尝试过使用Response<InputstreamResource>来返回文件，结果还是一样

下载和上传的代码如下，求大佬帮忙检查一下问题出在哪

下载部分：使用ResponseEntity<byte[]>对象返回，尝试配置了springmvc 的 ByteArrayConverter
 配置文件：
 <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>image/jpeg</value>
                        <value>image/png</value>
                        <value>application/pdf</value>
                        <value>image/gif</value>
                        <value>application/octet-stream</value>
                        <value>text/plain</value>
                    </list>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

 rest：
     /**
 * 下载文件请求
 *
 * @param fileId 文件ID
 * @return 文件流
 */
@CrossOrigin
@RequestMapping(value = "/download/{fileId}", method = RequestMethod.GET)
@ResponseBody
public ResponseEntity<byte[]> fileDownload(@PathVariable String fileId) throws  Exception {
    //从MongoDB获取文件
    GridFSDBFile file = fileService.getFileById(fileId);
    String fileType = file.getContentType();
    //设置文件ContentType
    MediaType mediaType = FileUtil.getEnableStr(fileType);
    //获取文件字节流
    byte[] outByte = FileUtil.gridFSBFileToByte(file);
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(mediaType);
    headers.setContentDispositionFormData("attachment",file.getFilename()+"."+fileType);
            //返回前端
    return new ResponseEntity<>(outByte, headers, HttpStatus.OK);
}

下载文件rest2:
 /**
 * 下载文件请求
 *
 * @param fileId 文件ID
 * @return
 */
@CrossOrigin
@RequestMapping(value = "/download2/{fileId}", method = RequestMethod.GET)
@ResponseBody
public ResponseEntity<InputStreamResource> fileDownload2(@PathVariable String fileId) throws  Exception {
    //从MongoDB获取文件
    GridFSDBFile file = fileService.getFileById(fileId);
    String fileType = file.getContentType();
    //设置文件ContentType
    MediaType mediaType = FileUtil.getEnableStr(fileType);
    InputStreamResource resource =  new InputStreamResource(file.getInputStream());
    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(mediaType);
    headers.setContentDispositionFormData("attachment",file.getFilename()+"."+fileType);
    //返回前端
    return new ResponseEntity<>(resource, headers, HttpStatus.OK);
}


service：
 @Override
public GridFSDBFile getFileById(String fileId) throws RestServiceException {
    GridFSDBFile file =     
gridFsTemplate.findOne(Query.query(Criteria.where("_id").is(fileId)));
    if (file == null) {
        throw new RestServiceException("找不到相关文件！请检查fileId");
    }
        return file;
}

上传部分：

    rest:
   /**
     * 接受前端上传的文件并存储至MongoDB
     *
     * @param file 前端上传的文件
     * @return 处理结果信息
     */
    @CrossOrigin
    @ResponseBody
    @RequestMapping(value = "/upload", method = RequestMethod.POST)
    public ReturnInfo fileUpload(@RequestParam MultipartFile file) throws Exception {
        ReturnInfo<Map> info = new ReturnInfo<>();
        if (!file.isEmpty()) {
            BufferedInputStream inputStream = new BufferedInputStream(file.getInputStream());
            String fileId = fileService.fileUpload(inputStream);
            info.setCode(ReturnInfo.OK);
            info.setMessage("上传成功！");
            Map<String, String> resultMap = new HashMap<>();
            resultMap.put("fileId", fileId);
            info.setData(resultMap);
            return info;
        } else {
            info.setMessage("文件不能为空");
            info.setCode(ReturnInfo.ERROR);
            return info;
        }

    }
    
    service：
      /**
 * 文件上传
 *
 * @param fileInput 文件输入流
 * @return mongodb对应文件id
 */
@Override
public String fileUpload(InputStream fileInput) throws RestServiceException {
    String fileType = FileUtil.getFileType(fileInput);
    System.out.println(fileType);
    //文件类型判断
    if (!FileUtil.ENABLE_TYPES.contains(fileType)) {
        throw new RestServiceException("不支持的文件类型！");
    }
    GridFSFile uploadFile = gridFsTemplate.store(fileInput, StringUtil.getUUID(), fileType);
    return uploadFile.getId().toString();
}