出现“不存在所需的请求部分'文件'”错误

Question

When I try to send a PUT request to Java Spring from the Angular frontend I receive a Required request part 'file' is not present error. I put the name as 'file' in FormData but I think it somehow doesn't see it like that.

When I use the same PUT request in Postman it does work.

This is my service in which the other methods do work:

@Injectable()
export class ExamService {
  examens: Examen[] = [];

  constructor(private http: HttpClient) {}

  getExams(): Observable<Examen[]> {
    return this.http.get<Examen[]>(APIURL + '/all');
  }

  getExamById(id): Observable<Examen> {
    return this.http.get<Examen>(APIURL + '/asobject/' + id);
  }

  updateExamById(id, exam: Examen) {
    const fd = new FormData();
    console.log(exam.file);
    fd.append('name', exam.naam);
    fd.append('file', exam.file);
    return this.http.put<Examen>(APIURL + '/update/' + id, fd);
  }
}

This is the payload that I am sending so it seems it does send it the right way:

------WebKitFormBoundarynGgRxEgh6IdsxOiR
Content-Disposition: form-data; name="name"

Exam1
------WebKitFormBoundarynGgRxEgh6IdsxOiR
Content-Disposition: form-data; name="file"

4.868,68
------WebKitFormBoundarynGgRxEgh6IdsxOiR--

My controller in Spring which shouldn't be wrong since Postman does work:

@PutMapping(value = "/update/{id}", consumes = "multipart/form-data")
public ResponseEntity UpdateExam(@RequestParam("file") MultipartFile file, @RequestParam("name") String name, @PathVariable("id") int id)
{
    Exam newExam = new Exam();
    newExam.setId(id);
    newExam.setSkelet(file.getOriginalFilename());
    newExam.setNaam(name);
    newExam.setCreatedAt(LocalDateTime.now());
    Exam exam2 = ExamFactory.update(newExam);
    examRepository.save(exam2);
    storageService.store(file);
    return created(URI.create("/skelet/exam/update/" + newExam.getId())).build();
}

Answer 1

You append the file with wrong way... Please use this way:

this.formData.append('file', file, file.name);

name

The name of the field whose data is contained in value.

value

The field's value. This can be a USVString or Blob (including subclasses such as File).

filename Optional

The filename reported to the server (a USVString), when a Blob or File is passed as the second parameter. The default filename for Blob objects is "blob". The default filename for File objects is the file's filename.