@ApiOperation(value = "文件上傳", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
    @PostMapping("/file/upload")
    @Transactional(rollbackFor = Exception.class)
    public ApiResult<String> upload(@RequestPart("file") MultipartFile file) {
        try {
            TFileUploadDet fileUpload = FileManageUtil.upload(file);
            return  ApiResult.data(fileUpload.getId());
        } catch (Exception e) {
            log.error(e.getMessage(),e);
            return ApiResult.fail(e.getMessage());
        }
    }

public static TFileUploadDet upload(MultipartFile file) {
        Assert.notNull(file, "文件不能為空");
		//獲取上傳文件名稱
        String originalFilename = file.getOriginalFilename();
        //獲取文件后綴名
        String suffix = originalFilename.substring(originalFilename.lastIndexOf('.'));
        String extName = suffix.substring(1);
        //校驗文件格式是否為規(guī)定
        Assert.isTrue(WjlxEnum.WJLX999.getExtNameList().contains(extName),"文件類型僅支持jpg/mp4/pdf,請確認!");
        String id = SecureUtil.md5(originalFilename + IdUtil.getSnowflakeNextIdStr());
        String fileName = id + suffix;
        String year = DateUtil.format(new Date(), "yyyy");
        String today = DateUtil.format(new Date(), "yyyy-MM-dd");
        //獲取文件存儲路徑
        String fileId = File.separator + year + File.separator + today + File.separator + fileName;
        Path path = Paths.get(filePath(fileId));
        //創(chuàng)建文件夾（存在文件夾就直接存在該文件夾下沒有文件夾就先創(chuàng)建文件夾在保存）
        FileUtil.mkParentDirs(path);
        InputStream inputStream = null;
        OutputStream outputStream = null;
		//文件流上傳文件
        try {
            inputStream = file.getInputStream();
            outputStream = Files.newOutputStream(path);
            IoUtil.copy(inputStream, outputStream);
            //一下為自定義返回參數(shù)，視情況而定
            TFileUploadDet fileUpload = new TFileUploadDet();
            fileUpload.setId(id);
            fileUpload.setWjmc(originalFilename);
            fileUpload.setWjlj(path.toString());
            fileUpload.setCreateTime(new Date());
            return fileUpload;
        } catch (IOException e) {
            throw new RuntimeException("文件上傳失敗", e);
        } finally {
            IoUtil.close(outputStream);
            IoUtil.close(inputStream);
        }
    }
/**
     * 獲取完整的文件路徑
     *
     * @param fileId 文件唯一標(biāo)識
     * @return 文件路徑
     */
    public static String filePath(String fileId) {
        return uploadFilePath + fileId;
    }

<dependency>
                <groupId>cn.hutool</groupId>
                <artifactId>hutool-core</artifactId>
                <version>5.8.6</version>
            </dependency>

@ApiOperation(value = "通過文件id下載文件")
    @PostMapping("/downloadById")
    public void downloadFileById(HttpServletRequest request, HttpServletResponse response, @RequestBody @Valid IdDTO idDTO) {
        String id = idDTO.getId();
        Assert.isTrue(StringUtils.isNotEmpty(id), "主表id不能為空");
        TFile tFile = fileService.getById(id);
        Assert.notNull(tFile, "要下載的文件不存在");
        String fileName = tFile.getFileName();
        request.getSession();
        //獲取頁面輸出流
        try (ServletOutputStream out = response.getOutputStream()) {
            String path = tFile.getFileLink();
            File file = new File(path);
            byte[] bytes = FileUtils.readFileToByteArray(file);
            // 設(shè)置響應(yīng)頭
            response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
            out.write(bytes);
            out.flush();
        } catch (IOException e) {
            log.error(e.getMessage());
            throw new RuntimeException("下載文件出錯");
        }
    }