Angular 4. File upload

Question

I use Angular 4 and I have this code.

uploadPhoto(file: File):Promise<any> {
  var formData = new FormData();
  formData.append('req', file);
  return this.http.post(`${this.urlApi}/uploadphoto`, formData, {
    withCredentials: false,
    body: formData,
  })
    .toPromise()
    .catch(this.handleError);  }

Then I debug my program on Java Spring. I have in debug panel only parametr "req", but not multipart file. I set headers "multipart/form-data" and "undefined". I set "formData.append('req', file[0]); Also, I used this code:

uploadPhoto2(file:File){
  var formData = new FormData();
  formData.append('file', file);
  var request = new XMLHttpRequest();
  request.open('POST', `${this.urlApi}/uploadphoto`);
  request.send(formData);
}

I have the same results. In console of chrome I see: Content-Type:multipart/form-data; boundary=----WebKitFormBoundarycE8MNSpWUCwCDLLB

When I send data from Postman (chrome exstension) I have succesfull result. Debug in Java Debug in chrome

Answer 1

This code is working very well for me :

HTML CODE:(this is for image)

<div class="form-group">
 <label for="usr">Upload your new photo(Optional):</label> <input type="file"  accept=".jpg,.png,.jpeg" (change)="attachFile($event)">
 <br>
 <img src="{{imageSrc}} | defaultPipe "   height="250" weight="250" alt="Image preview..." />
</div>

ANGULAR CODE :

 attachFile(event) : void {
     var reader = new FileReader();
     let _self = this;

     reader.onload = function(e) {
       _self.imageSrc = reader.result;
       console.log(_self.imageSrc);
     };
     reader.readAsDataURL(event.target.files[0]);
    }

Notes: in method you must define a local variable for this operator to use it in function. In imageSrc you have the base64 byte array of file.