通过单个请求发送JSON和图像。角形+弹簧防尘套

弹簧座控制器

@PostMapping(
    value = "/post",
    produces = MediaType.APPLICATION_JSON_VALUE,
    consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.MULTIPART_FORM_DATA_VALUE}
)
public ResponseEntity<User> handleFileUpload(@RequestParam("user") User user, @RequestPart("file") MultipartFile file) {
    // do something with User and file
    return ResponseEntity.ok().build();
}

角度服务

@Injectable()
export class UploadFileService {

  constructor(private http: HttpClient) { }
  pushFileToStorage(file: File): Observable<HttpEvent<{}>> {
    let formdata: FormData = new FormData();
    formdata.append('file', file);
    formdata.append('user', JSON.stringify(new User('John', 12)))

    const req = new HttpRequest('POST', '/post', formdata, {
      reportProgress: true,
    });

    return this.http.request(req);
  }
}

当我尝试发送请求时,我收到 500 Internal Server Error.

这是一个请求头

POST /post HTTP/1.1
Host: localhost:4200
Connection: keep-alive
Content-Length: 152881
Accept: application/json, text/plain, */*
Content-Type: multipart/form-data; boundary=----WebKitFormBoundarydaQb5yaWw2xu1V9r
Accept-Encoding: gzip, deflate, br
Accept-Language: en-US,en;q=0.9

请求有效负载

------WebKitFormBoundarydaQb5yaWw2xu1V9r
Content-Disposition: form-data; name="file"; filename="Screen Shot 2017-10-24 at 8.49.13 PM.png"
Content-Type: image/png


------WebKitFormBoundarydaQb5yaWw2xu1V9r
Content-Disposition: form-data; name="user"

{"name":"John","age":12}
------WebKitFormBoundarydaQb5yaWw2xu1V9r--

注意:如果在Spring rest控制器中,我将参数类型User更改为字符串,它就会工作。

问题:如何从Angular发送请求,以便在Spring上获取用户和多部分文件,而不是字符串。