http - 如何在 Dart 中设置多部分请求的超时？

Question

这是我的MultiPartRequest代码

var request =
            http.MultipartRequest("POST", Uri.parse(EMPLOYEE_PUNCH_IN_URL));

        request.fields['uid'] = userId;
        request.fields['location'] = location;
        request.fields['punchin_time'] = punchInTime;
        request.fields['punchin_location_name'] = address;

        var multiPartFile = await http.MultipartFile.fromPath(
            "photo", imageFile.path,
            contentType: MediaType("image", "$extension"));
        request.files.add(multiPartFile);
        http.StreamedResponse response = await request.send();

        var responseByteArray = await response.stream.toBytes();

        employeePunchInModel = standardSerializers.deserializeWith(
            EmployeePunchInModel.serializer,
            json.decode(utf8.decode(responseByteArray)));
        ......

我知道如何为正常的 http 请求设置超时。我已点击此链接

Set timeout for HTTPClient get() request

我尝试通过以下方式添加超时功能，但它不起作用，我的请求已完成

1.

 var multiPartFile = await http.MultipartFile.fromPath(
            "photo", imageFile.path,
            contentType: MediaType("image", "$extension")).timeout(const Duration(seconds: 1)); 

2.

http.StreamedResponse response = await request.send().timeout(const Duration(seconds: 1));

3.

var responseByteArray = await response.stream.toBytes().timeout(const Duration(seconds: 15));

但是以上超时都不起作用。

Answer 1

使用http package ，这是我的方法:

1. 创建一个我们将用于 onTimeOut 回调的流式响应

StreamedResponse timeOutResponse({
  @required String httpMethod,
  @required dynamic error,
  @required String url,
}) { 
  Map<String, dynamic> body = {
    'any': 'value',   
    'you': 'want for $error',
  };

  int statusCode = 404;  
  Uri destination = Uri.parse(url);
  String json = jsonEncode(body);
  
  return StreamedResponse(
    Stream.value(json.codeUnits),
    statusCode,
    request: Request(httpMethod, destination),
  );
}

使用 Mahesh Jamdade 中修改后的 http 多部分函数回答

Future<http.Response> makeAnyHttpRequest(String url,
  Map<String, dynamic> body,
  {Function onTimeout,
  Duration duration = const Duration(seconds: 10)}) async {

     final request = http.MultipartRequest(
         'POST',
          Uri.parse('$url'),
       );
     
     final res = await request.send().timeout(
         duration,
         onTimeout: () {
           return timeOutResponse(
             httpMethod: 'MULTIPART POST',
             error: 'Request Time Out',
             url: url,
           );
         },
       );

     return await http.Response.fromStream(res);
  }

这样，您就可以返回 onTimeOut Http Response，而不是超时异常。