springboot文件上传

SimpleDateFormat sdf=new SimpleDateFormat("/yyyy/MM/dd/");
    @PostMapping("upload")
    public Map<String,Object> fileUpload(MultipartFile file, HttpServletRequest request){
        Map<String,Object> map=new HashMap<>();
        String originalFilename = file.getOriginalFilename();
        if (!originalFilename.endsWith(".pdf")){
            map.put("status","error");
            map.put("msg","文件类型不对");
            return map;
        }
        String format = sdf.format(new Date());
        //项目当前路径
        String realPath=request.getServletContext().getRealPath("/")+ format;
        File folder = new File(realPath);
        if (!folder.exists()){
            folder.mkdirs();
        }
        String newName=UUID.randomUUID().toString()+".pdf";
        try {
            file.transferTo(new File(folder,newName));
            String url=request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+format+newName;
            map.put("status","success");
            map.put("url",url);
        } catch (IOException e) {
            map.put("status","error");
            map.put("msg",e.getMessage());
        }
        return map;
    }