flutter send empty file to server - api

Question

Hi i'm trying to upload a file to a server via a flutter app but the file is always empty.
it was working fine and after that it stopped working.
here is my code :
static uploadImageToServer(String image) async {
File imageFile = new File(image);
Map<String, String> headers = {
'Content-Type': 'multipart/form-data',
'Accept-Charset': 'UTF-8'
};
var stream = new http.ByteStream(DelegatingStream.typed(imageFile.openRead()));
var length = await imageFile.length();
print(imageFile.path);
var uri = Uri.parse("http://planning.test/test_image");
var request = new http.MultipartRequest("POST", uri);
var multipartFile = new http.MultipartFile('File', stream, length,
filename: "test_image_failure.jpg");
request.headers.addAll(headers);
request.fields['Destination'] = '/';
print("**********");
print(multipartFile.filename);
print(uri);
print(multipartFile.length);
print("**********");
request.files.add(multipartFile);
print(request.contentLength);
var response = await request.send();
print(response.statusCode);
response.stream.transform(utf8.decoder).listen((value) {
print(value);
});
}
and with dio package
_dioUpload(String imageFile)async {
var dio = Dio();
var formData = FormData();
formData.files.add(MapEntry(
"File",
await MultipartFile.fromFile(imageFile, filename: "xx.png"),
));
print(formData.files.first.value.length);
var response = await dio.post(
"http://planning.test/test_image",
data: formData,
onSendProgress: (received, total) {
if (total != -1) {
print((received / total * 100).toStringAsFixed(0) + "%");
}
},
);
print(response);
}
i don't understand what is happening everything look fine and the file exist.
thx

Answer 1

I'm using the retrofit for flutter and to send an empty file I got it as follows.
File.fromRawPath(Uint8List.fromList([0]))
Retrofit example
#PUT('profile')
#FormUrlEncoded()
Future<void> update(#Header("Authorization") String token,
#Field() String name, #Field() String surname, #Part() File avatar);
Example
await myapi.update("_token_","Sr", "Burton", File.fromRawPath(Uint8List.fromList([0])));