使用angular / spring上传文件时出现MultipartException

Question

当我尝试使用angular / spring上传文件时，出现异常：org.springframework.web.multipart.MultipartException：当前请求不是一个多部分请求，但是当我使用邮递员尝试它时可以正常工作

我的代码：角形

upload.service.ts：

public save(file: File) {
    this.headers.set('Content-Type', 'multipart/form-data');
    const formdata: FormData = new FormData();
    formdata.append('file', file);
    return this.http.post(this.baseUrl + "upload", formdata, { headers: 
    this.headers }).map(resp => resp.json());

}

上传组件：

  currentFileUpload: File;

  constructor(private uploadService: UploadService) { }

  ngOnInit() {
  }

  selectFile(event) {
    this.currentFileUpload = event.target.files[0];
  }

  uploadFile() {
    this.uploadService.save(this.currentFileUpload).subscribe(resp => {
      console.log(resp);
    },
      err => {
        console.log(err);
      });
  }

html代码：

<div class="custom-file">
  <input type="file" (change)="selectFile($event)" class="custom-file-input" id="customFile">
  <label class="custom-file-label" for="customFile">choisissez un fichier (*pdf, *csv ,*docs)</label>
  <button class="btn btn-danger" (click)="uploadFile()">Upload</button>
</div>

代码后端：

@PostMapping("/api/upload")
public String handleFileUpload(@RequestParam("file") MultipartFile file) {
    String name = file.getOriginalFilename();
     if (!file.isEmpty()) {
         try {
             byte[] bytes = file.getBytes();
             BufferedOutputStream stream =
                     new BufferedOutputStream(new FileOutputStream(new File("src/upload/"+name)));
             stream.write(bytes);
             stream.close();
             return "You successfully uploaded " + name + " into " + name + "-uploaded !";
         } catch (Exception e) {
             return "You failed to upload " + name + " => " + e.getMessage();
         }
     } else {
         return "You failed to upload " + name + " because the file was empty.";
     }

}

当我与邮递员尝试时：

春季异常：