@Bean
 public MultipartResolver resolver() {
     return new CommonsMultipartResolver();
 }

@PostMapping("/uploadFile")
 @ResponseBody
 public Map<String, Object> uploadFile(@RequestParam("file") MultipartFile file) throws IOException {
     String originalFilename = file.getOriginalFilename();
     file.transferTo(new File("d:/" + originalFilename));
     Map<String, Object> map = new HashMap<>();
     map.put("code", 1);
     return map;
 }