[ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: NoSuchMethodError: The method 'matchAsPrefix' was called on null.

[shreyash333]

Hover doctor

[√] Flutter (Channel beta, 1.26.0-17.6.pre, on Microsoft Windows [Version 10.0.19041.867], locale en-US) • Flutter version 1.26.0-17.6.pre at C:\flutter • Framework revision a29104a69b (6 weeks ago), 2021-02-16 09:26:56 -0800 • Engine revision 21fa8bb99e • Dart version 2.12.0 (build 2.12.0-259.12.beta)

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.3) • Android SDK at C:\Users\Asus\AppData\Local\Android\sdk • Platform android-30, build-tools 30.0.3 • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01) X Android license status unknown. Run flutter doctor --android-licenses to accept the SDK licenses. See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[√] Chrome - develop for the web • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Android Studio (version 4.1.0) • Android Studio at C:\Program Files\Android\Android Studio • Flutter plugin can be installed from: https://plugins.jetbrains.com/plugin/9212-flutter • Dart plugin can be installed from: https://plugins.jetbrains.com/plugin/6351-dart • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b01)

[√] VS Code (version 1.54.3) • VS Code at C:\Users\Asus\AppData\Local\Programs\Microsoft VS Code • Flutter extension version 3.20.0

[√] Connected device (3 available) • AOSP on IA Emulator (mobile) • emulator-5554 • android-x86 • Android 9 (API 28) (emulator) • Chrome (web) • chrome • web-javascript • Google Chrome 89.0.4389.90 • Edge (web) • edge • web-javascript • Microsoft Edge 89.0.774.57

$ hover doctor
hover: Running on linux
hover: Docker installed: true
hover: Sharing flutter version
[...]

Error output

[ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: NoSuchMethodError: The method 'matchAsPrefix' was called on null. E/flutter (14919): Receiver: null Tried calling: matchAsPrefix("application/x-www-form-urlencoded", 0) E/flutter (14919): #0 StringScanner.matches (package:string_scanner/src/string_scanner.dart:171:26) E/flutter (14919): #1 StringScanner.scan (package:string_scanner/src/string_scanner.dart:128:21) E/flutter (14919): #2 new MediaType.parse. (package:http_parser/src/media_type.dart:48:17) E/flutter (14919): #3 wrapFormatException (package:http_parser/src/utils.dart:13:16) E/flutter (14919): #4 new MediaType.parse (package:http_parser/src/media_type.dart:46:7) E/flutter (14919): #5 Request._contentType (package:http/src/request.dart:157:22) E/flutter (14919): #6 Request.encoding= (package:http/src/request.dart:62:23) E/flutter (14919): #7 BaseClient._sendUnstreamed (package:http/src/base_client.dart:78:35) E/flutter (14919): #8 BaseClient.post (package:http/src/base_client.dart:32:7) E/flutter (14919): #9 post. (package:http/http.dart:70:16) E/flutter (14919): #10 _withClient (package:http/http.dart:166:20) E/flutter (14919): #11 post (package:http/http.dart:69:5)

[shreyash333]

Map<String, dynamic> jsonMap = { "token": jwttoken, "student_id": user.student_id.toString() };

var res = await http.post('http://10.0.2.2:12345/getCurrentDB',
    body: jsonMap,
    headers: {
      "Accept": "application/json",
      "Content-Type": "application/x-www-form-urlencoded"
    },
    encoding: Encoding.getByName("utf-8"));