How to post JSON String NOT Object in request body?

Question

The body is String similar to this. I tried many different ways as below, but none worked.

await http.post(
  Uri.parse(url),
  headers: {
    "content-type": "application/json",
  },
  body: "3ea9554d-7a1f-4f20-f6f5-08da74d069a8",      // "'a' is invalid within a number, immediately after a sign character
  // body: "\"3ea9554d-7a1f-4f20-f6f5-08da74d069a8\"",  // The JSON value could not be converted to
  // body: jsonEncode("3ea9554d-7a1f-4f20-f6f5-08da74d069a8"), // The JSON value could not be converted to
  // body: jsonEncode("\"3ea9554d-7a1f-4f20-f6f5-08da74d069a8\""), // The JSON value could not be converted to
  // body: jsonEncode(jsonDecode('3ea9554d-7a1f-4f20-f6f5-08da74d069a8')),  // FormatException: Missing expected digit (at character 3)
  // body: jsonEncode(jsonDecode("\"3ea9554d-7a1f-4f20-f6f5-08da74d069a8\"")),  // The JSON value could not be converted to
);

Yes, I run the api in postman and it works without any problems. — Hasan El-Hefnawy, Aug 04 '22 at 19:00
https://stackoverflow.com/questions/69274083/flutter-how-to-pass-form-data-to-api/69274760#69274760 checkout this — Wali Khan, Aug 04 '22 at 19:00
@WaliKhan Thank you so much. Please, post your answer so that I can accept it as a solution. — Hasan El-Hefnawy, Aug 04 '22 at 21:19

Hasan El-Hefnawy · Answer 1 · 2022-08-04T21:25:13.230

1

Thanks to the answer given by Wali Khan. The solution is

final request = http.Request('POST', Uri.parse(url));
request.headers.addAll({
  "content-type": "application/json",
});
request.body = json.encode("3ea9554d-7a1f-4f20-f6f5-08da74d069a8");
http.StreamedResponse response = await request.send();

edited Aug 04 '22 at 21:25

answered Aug 04 '22 at 21:07

Hasan El-Hefnawy

1,249
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score 1 · Accepted Answer · answered Aug 04 '22 at 21:22

1

Use postman to autogenerate code like this

answered Aug 04 '22 at 21:22

Wali Khan

586
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score 0 · Answer 3 · answered Aug 04 '22 at 19:02

0

Since you set the content-type to application/json, you can't pass a string, only an object, like:

body: jsonEncode({"value": "3ea9554d-7a1f-4f20-f6f5-08da74d069a8"})

To pass your string as you'd like, set the content type like this:

"content-type": "text/plain"

But according to the documentation you can try to remove the headers part completely, since it seems that it will be text/plain automatically if you pass a string as body.

answered Aug 04 '22 at 19:02

Peter Koltai

8,296
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Using text/plain returns 415 Unsupported Media Type which is also the same result I get on Postman when using text/plain instead of application/json. – Hasan El-Hefnawy Aug 04 '22 at 19:13
Maybe the endpoint does not allow plain text body then. – Peter Koltai Aug 04 '22 at 19:15

How to post JSON String NOT Object in request body?

3 Answers3

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