1.單檔案上傳

    private String uploadPath="D:\\tomcat\\apache-tomcat-7.0.81-windows-x64\\apache-tomcat-7.0.81\\webapps\\img\\";

    private String URL="http://127.0.0.1:8880/img/";
    /**
     * 單個檔案上傳   檔案上傳成功後返回檔案的訪問路徑
     * @param file
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/upload",method = RequestMethod.POST)
    public Msg upload(@RequestParam("file")MultipartFile file) {
        if(!file.isEmpty()) {
            File fil=new File(uploadPath+file.getOriginalFilename());
            try {
                BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream(fil));
                out.write(file.getBytes());
                out.flush();
                out.close();
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                return ResultUtil.error(200, "檔案上傳失敗{}" + e.getMessage());
            } catch (IOException e) {
                e.printStackTrace();
                return ResultUtil.error(200, "檔案上傳失敗{}" + e.getMessage());
            }
            return ResultUtil.success(URL+fil.getName());       //返回上傳檔案的訪問路徑   getAbsolutePath()返回檔案上傳的絕對路徑
        }else {
            return ResultUtil.error(201, "檔案上傳失敗,檔案為空");
        }
    }
 

    private String uploadPath="D:\\tomcat\\apache-tomcat-7.0.81-windows-x64\\apache-tomcat-7.0.81\\webapps\\img\\";

    private String URL="http://127.0.0.1:8880/img/";
    /**
     * 多檔案上傳 並返回各個檔案的訪問路徑
     * @param files
     * @return
     */
    @ResponseBody
    @RequestMapping(value = "/upload/batch", method = RequestMethod.POST)
    public Msg batchUpload(@RequestParam("files")MultipartFile[] files) {

        String uploadedFileName = Arrays.stream(files).map(x -> x.getOriginalFilename())
                .filter(x -> !StringUtils.isEmpty(x)).collect(Collectors.joining(" , "));
        if (StringUtils.isEmpty(uploadedFileName)) {
            return ResultUtil.error(201,"檔案上傳失敗,檔案為空");
        }
        List<String> path=new ArrayList<>();
        try {
           path=  saveUploadedFiles(Arrays.asList(files));
        } catch (IOException e) {
            return ResultUtil.error(201,"檔案上傳異常"+e.getMessage());
        }
        return ResultUtil.success(path);
    }


    private  List<String> saveUploadedFiles(List<MultipartFile> files) throws IOException {
       List<String> paths=new ArrayList<>();
        for (MultipartFile file : files) {
            if (file.isEmpty()) {
                continue;
            }
            byte[] bytes = file.getBytes();
            Path path = Paths.get(uploadPath + file.getOriginalFilename());
            paths.add(URL + file.getOriginalFilename());            //儲存上傳檔案的訪問路徑
            Files.write(path, bytes);
        }
      return paths;
    }
 

請求效果圖：

Java 8 中的 Stream API 詳解：Stream詳解