How to download binary file

Question

I want to download a binary file which is PDF and save it into my device. The file comes from API response. My response.body is like this:

Here is my code:

void downloadFile() async {
  String url = Uri.encodeFull('https://API_URL');
  http.Response response = await http.post(url, headers: {"Accept": "application/json", HttpHeaders.authorizationHeader: 'Bearer '},});
  print(response.body);
}

How can I use response.body to download the PDF file?

Answer 1

Use response.bodyBytes:

void downloadFile(File f) async {
  var url = Uri.encodeFull('https://API_URL');
  var response = await http.post(url, headers: {HttpHeaders.authorizationHeader: 'Bearer '},});
  await f.writeAsBytes(response.bodyBytes);
}

I removed the Accept header as it made no sense. You're hinting the server that you'll expect JSON, whereas you really want a PDF.

Answer 2

if you using Dio then you can use the below code.

await dio.post(finalUrl,
  options: Options(
      responseType: ResponseType.bytes,
      headers: headers,),
  data: encodedBody,);