所需的请求部分“文件”不存在] springboot 客户端

Question

我在客户端有这个代码：

          RestTemplate restTemplate = new RestTemplate();
          File file = new File("C:\\temp\\aadocejem.doc");
          MultiValueMap<String, Object> map = new LinkedMultiValueMap<String, Object>();

          map.add("file", file);


          String result = restTemplate.postForObject(url+"/doc_file", map, String.class);

而这段代码就是你上面所说的：

 @PostMapping("/doc_file")
    public ResponseEntity<File> docFileV1(
        @RequestParam("file") MultipartFile originalDocFile) {

        return ResponseEntity.ok(docFileService.processDocFile(originalDocFile));

    }

它在服务器上给我的错误：已解决 [org.springframework.web.multipart.support.MissingServletRequestPartException: required request part 'file' is not present]

它在客户端给我的错误： org.springframework.web.client.HttpClientErrorException$BadRequest: 400 : [{"timestamp":"2020-04-23T10:55:32.258+0000","status": 400,"error":"Bad Request","message":"所需的请求部分'文件'不存在","trace":"org.springframework.web.multipart.support.MissingServlet... (5758 字节) ]

Answer 1

这不适用于 postForObject。

使用 postForEntity 代替：

HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.MULTIPART__FORM__DATA);

MultiValueMap<String, Object> body = new LinkedMultiValueMap<>();
body.add("file", new FileSystemResource(file));

HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity<>(body, headers);

RestTemplate restTemplate = new RestTemplate();
ResponseEntity<String> response = restTemplate.postForEntity(url+"/doc_file", requestEntity, String.class);