Ошибка error host lookup

You should try following:

Try run application in debug mode if its working fine and not working in release mode then it might be related to permission issue so add permissions(INTERNET, ACCESS_NETWORK_STATE) in manifest file.

• your_project_root_directory/android/app/src/debug/AndroidManifest.xml
• your_project_root_directory/android/app/src/main/AndroidManifest.xml
• your_project_root_directory/android/app/src/profile/AndroidManifest.xml

If not included then add permissions:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

If its not working in debug mode, then check either your url is correct by hitting in postman. If its working in postman then you should execute your webservice in this way:

Add dependency in pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter

  http: 0.13.3

After adding http:0.13.3 then click on Pub get button If its executed with code 0 then it means its successfully added to your project.

in your dart file import http.dart:

import 'package:http/http.dart';

Now write this code to execute webservice:

var url = Uri.parse('some-url-login?username=abc&&password=xyz');
var response = await get(url, headers: {
          'Content-Type': 'application/json',
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Credentials': 'true',
          'Access-Control-Allow-Headers': 'Content-Type',
          'Access-Control-Allow-Methods':
          'GET,PUT,POST,DELETE'
        });
if (response.statusCode == 200) {
 // success
} else if(response.statusCode == 404){
 // not found
} else if(response.statusCode == 500){
 // server not responding.
} else {
 // some other error or might be CORS policy error. you can add your url in CORS policy. 
}

I hope it will help you. Chill!

You should try following:

Try run application in debug mode if its working fine and not working in release mode then it might be related to permission issue so add permissions(INTERNET, ACCESS_NETWORK_STATE) in manifest file.

• your_project_root_directory/android/app/src/debug/AndroidManifest.xml
• your_project_root_directory/android/app/src/main/AndroidManifest.xml
• your_project_root_directory/android/app/src/profile/AndroidManifest.xml

If not included then add permissions:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

If its not working in debug mode, then check either your url is correct by hitting in postman. If its working in postman then you should execute your webservice in this way:

Add dependency in pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter

  http: 0.13.3

After adding http:0.13.3 then click on Pub get button If its executed with code 0 then it means its successfully added to your project.

in your dart file import http.dart:

import 'package:http/http.dart';

Now write this code to execute webservice:

var url = Uri.parse('some-url-login?username=abc&&password=xyz');
var response = await get(url, headers: {
          'Content-Type': 'application/json',
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Credentials': 'true',
          'Access-Control-Allow-Headers': 'Content-Type',
          'Access-Control-Allow-Methods':
          'GET,PUT,POST,DELETE'
        });
if (response.statusCode == 200) {
 // success
} else if(response.statusCode == 404){
 // not found
} else if(response.statusCode == 500){
 // server not responding.
} else {
 // some other error or might be CORS policy error. you can add your url in CORS policy. 
}

I hope it will help you. Chill!

Problem Description:

Whenever I try to do an http call after about 20 seconds I get in the console the following error:

E/flutter ( 8274): [ERROR:flutter/shell/common/shell.cc(184)] Dart Error: Unhandled exception:
E/flutter ( 8274): SocketException: Failed host lookup: 'flutter-project-xxxxx.firebaseio.com' (OS Error: No address associated with hostname, errno = 7)

This error happens for every method and every route I call through the app http package.

I’m developing a flutter app on Windows, using an AVD virtual device from Android Studio.

Versions:

  http: ^0.12.0+1
  flutter: 1.0

Cases:

1. From home or though tethering from my phone:
   connectivity works fine on every part of the virtual device

2. From my work network (behind the firewall):

Only with Android Web View, I can browse the internet without any problem (i can even call the same url, I use in the code and it works).
I get a connection error when using any other application (Chrome, Google Play, ecc…) in the virtual device, and specifically the “SocketException”, when testing my app.

What is the difference between the calls coming from that app?
Is there a way to route my app calls the same way as the ones in the webview?

Thanks!

Solution – 1

Add <uses-permission android:name="android.permission.INTERNET" /> to your AndroidManifest.xml file.

Solution – 2

Adding internet permission is not only a solution.

You also have to make sure that you are online whether it is mobile or emulator

1. Make sure you are online whether it is mobile or emulator

2. Make sure you have given internet permission in your app’s android/app/src/main/AndroidManifest.xml

   <uses-permission android:name="android.permission.INTERNET"/>

Solution – 3

I added <uses-permission android:name="android.permission.INTERNET" /> to
my manifest. I then had to restart the emulator for internet to work.

Solution – 4

If you are using an emulator make sure that the mobile data is active

Solution – 5

The problem is basically coming when device is trying to access any internet resources,to fix add the
to AndroidManifest.xml file @android/app/src location.

Solution – 6

Check if the wifi is connected or not. Mine worked after restarting the wifi.

Solution – 7

If you are getting this error while using the flutter_socket_io plugin, don’t forget to initialize the socket i.e socketIO.init(); socketIO.connect(); before attempting to subscribe to it. I received the same error as that indicated above when I omitted it.

Solution – 8

Check if you have enabled offline work in the gradle settings.
File-> Settings -> Build -> Build Tools -> Offline work

If its enabled or checked then uncheck it.

Solution – 9

• Make sure the internet is on (both on the phone and the PC)
• also, make sure the server is working properly
• check your URL properly

Solution – 10

Also, might good to look at the ‘Proxy settings’ inside the ‘Extended controls’ of the emulator.

The way it worked for me was to change to use the ‘No Proxy’ setting.

Solution – 11

Make sure your Mobile device or Emulator is connected to the internet

Solution – 12

When i enabled wifi on my device, it worked fine.

Solution – 13

Translated: In my case, the computer had internet, but the emulator did not. I configured the connection on the emulator and solved it.

Solution – 14

Double-check / make sure you have

<uses-permission android:name="android.permission.INTERNET" />
in your app’s android/app/src/main/AndroidManifest.xml

Solution – 15

Even after adding

<uses-permission android:name="android.permission.INTERNET"/>

in your android/app/src/main/AndroidManifest.xml, if you’re still finding trouble then

There maybe an error with the website’s server IP address like:

Server IP address could not be found

It’s better to wait for some time and make sure to restart wifi, it worked for me.

Solution – 16

Make sure your Emulator or your device connected to the internet.
if your Emulator could not connect to the internet use a VPN.

Solution – 17

Sometimes, other wifi can have interference with your connected wifi, which can cause this error as well. Try to set your connected wifi’s channel to auto or away from other wifi’s channels.

Solution – 18

Even I had the same issue. I restarted my emulator and it worked!!

Solution – 19

By enabling WIFI it works for me, and make sure you also added the internet permission in the android manifest it added automatically also but you have to make sure. if still not then invalidate caches and restart hope it works

Solution – 20

I had the same problem while running the app on an emulator.

My laptop was connected to the internet through my phone’s mobile hotspot.
But apparently the emulator was unable to access the internet

Later, I switched to my Wi-Fi Router connection and the application proceeded smoothly as expected.

I’m not sure, but is there any special access to be granted?

Tip: Try googling something on the emulator to check internet connectivity

Solution – 21

Go for AVD manager, then choose your emulator, on Actions menu click down option sign, then choose wipe data, then restart your emulator. It works for me.

Solution – 22

if you’re using vscode you would get gai_error=0 that’s if the http is connected successfully

Here is the right place to place the internet permission because it was quite challenging to know the location

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.appName">
<uses-permission android:name="android.permission.INTERNET" />

run the flutter run command on cmd or visual studio code terminal

Solution – 23

For me it was just bad url with function «Uri.https(…)» in Flutter.
Check if the address is correct with your browser

Solution – 24

The problem for me was that I was using a VPN. The emulator didn’t have internet access when connected to the VPN on my computer. It might help someone.

Solution – 25

In my case it was because my phone was not connected to internet

Just enable internet connexion

Solution – 26

I deliberately disconnected my emulator wifi to see what would happen (as there could be cases where no internet is available). The error led me here, but, all I see are workarounds and not error handling. Really, the app should be able to handle the error gracefully and not crash out because of a lack of connection.

So far, all I have done is to catch the error and if the return code is -1 (or anything other than a 200), I know I have a problem and can make the app respond appropriately.

var request = new http.MultipartRequest("POST", uri);

// multipart that takes file
var multipartFile = new http.MultipartFile('file', stream, length,
    filename: fileToUpload.path);

// add file to multipart
request.files.add(multipartFile);

// send
try {
  var response = await request.send();
  print(response.statusCode);

  // listen for response
  response.stream.transform(utf8.decoder).listen((value) {
    print(value);
  });

  return response.statusCode;
}
catch (e)
{
  return -1;
}

Solution – 27

It’s definitely internet issue as others have stated. @petro and @Tushar Nikam response put me in the right direction. My emulator was in airplane mode, but I don’t know how; it’s the one I use 90% of the time. I’d advise to check for anything that might block internet connectivity.

Solution – 28

check your url address , In my case I was using a wrong url.

Solution – 29

You should try following:

Try run application in debug mode if its working fine and not working in release mode then it might be related to permission issue so add permissions(INTERNET, ACCESS_NETWORK_STATE) in manifest file.

• your_project_root_directory/android/app/src/debug/AndroidManifest.xml
• your_project_root_directory/android/app/src/main/AndroidManifest.xml
• your_project_root_directory/android/app/src/profile/AndroidManifest.xml

If not included then add permissions:

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

If its not working in debug mode, then check either your url is correct by hitting in postman. If its working in postman then you should execute your webservice in this way:

Add dependency in pubspec.yaml:

dependencies:
  flutter:
    sdk: flutter

  http: 0.13.3

After adding http:0.13.3 then click on Pub get button If its executed with code 0 then it means its successfully added to your project.

in your dart file import http.dart:

import 'package:http/http.dart';

Now write this code to execute webservice:

var url = Uri.parse('some-url-login?username=abc&&password=xyz');
var response = await get(url, headers: {
          'Content-Type': 'application/json',
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Credentials': 'true',
          'Access-Control-Allow-Headers': 'Content-Type',
          'Access-Control-Allow-Methods':
          'GET,PUT,POST,DELETE'
        });
if (response.statusCode == 200) {
 // success
} else if(response.statusCode == 404){
 // not found
} else if(response.statusCode == 500){
 // server not responding.
} else {
 // some other error or might be CORS policy error. you can add your url in CORS policy. 
}

I hope it will help you. Chill!

Solution – 30

I’m using arch Linux.

Linux arch 5.14.7-arch1-1

And Flutter version

Flutter 2.2.1 

Dart version

Dart 2.13.1

Code editor

1.58.0

In my case turning on wifi solved the problem.

Solution – 31

For me, the problem was that my emulator had network connections (LTE and Wi-Fi) disabled.

Solution – 32

In My case I opened the emulator before I connected to the WIFI to system.When network(WIFI) has connected to my system but unable to connect to emulator .
Due to no internet access to the Emulator,this issues occurs.I resolved this issues by this way.

Solutions:

Connected network access to the system then I Closed the emulator and re-open it. Install applications ,run application and open it .And Finally works every API works fine.

Solution – 33

Make sure you have added the in android/app/src/main/AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

Solution – 34

The DNS settings on my mac were invalid…just use 8.8.8.8 without any internal DNS routing addresses

Is there an existing issue for this?

• I have searched the existing issues
• I have read the guide to filing a bug

Steps to reproduce

Just make a network request.

For example, using the basic http package.

Also relevant when using other packages, such as Dio.
The same error, and in the same versions of Flutter.

Therefore, I think they have the same root.

The bug is very critical, as already many communities of various applications complain about it.

I have given the simplest code example below.
The main essence is in the line:

await http.get(Uri.parse('https://flutter.dev'));

This request throws an exception:
SocketException (SocketException: Failed host lookup: 'flutter.dev' (OS Error: ... , errno = 11004))

This error appears on ANY host of the many that I have tried.
That is, the problem is not in a particular host.

This problem is relevant for Windows (which discards many other similar problems that can be found on the Internet and which are associated with missing permissions on the Android system). It’s not that problem.

I’ve reproduced this bug in the latest master as well as in the latest stable release.
On the Internet people advise to downgrade Flutter to version 3.10.5, where this problem does not reproduce. I personally haven’t tried it yet, but I suspect that all versions after 3.10.5 have this bug.
But downgrading to that version is not an option for me anyway.

Please fix this bug as soon as possible.
Yes, this exception is skippable, but it creates debugging inconvenience in many cases.
Moreover, this problem is relevant for many.

Thank you!

Expected results

No exception

Actual results

This request throws an exception:
SocketException (SocketException: Failed host lookup: 'flutter.dev' (OS Error: ... , errno = 11004))

Code sample

Code sample

import 'package:flutter/material.dart';
import 'package:http/http.dart' as http;

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  Future<void> _test() async {
    try {
      await http.get(Uri.parse('https://flutter.dev'));
    } catch (ex) {
      // ignore: use_build_context_synchronously
      showDialog(
        context: context,
        builder: (context) {
          return AlertDialog(
            title: const Text('Result'),
            content: Text(
              ex.toString(),
            ),
            actions: <Widget>[
              TextButton(
                child: const Text('Ok'),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
            ],
          );
        },
      );
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      floatingActionButton: FloatingActionButton(
        onPressed: _test,
        child: const Icon(Icons.error),
      ),
    );
  }
}

Screenshots or Video

No response

Logs

No response

Flutter Doctor output

Doctor output

[✓] Flutter (Channel master, 3.14.0-8.0.pre.17, on Microsoft Windows [Version 10.0.22621.2134], locale ru-UA)
    • Flutter version 3.14.0-8.0.pre.17 on channel master at C:\SDK\Flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 6f227c0784 (2 days ago), 2023-08-18 19:04:15 -0700
    • Engine revision f4bffdcf85
    • Dart version 3.2.0 (build 3.2.0-87.0.dev)
    • DevTools version 2.26.1

[✓] Windows Version (Installed version of Windows is version 10 or higher)

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.2)
    • Android SDK at C:\SDK\Android
    • Platform android-33-ext5, build-tools 33.0.2
    • Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
    • Java version OpenJDK Runtime Environment (build 17.0.6+0-b2043.56-9586694)
    • All Android licenses accepted.

[✓] Chrome - develop for the web
    • CHROME_EXECUTABLE = C:\Program Files\Chromium\chrome

[✓] Visual Studio - develop Windows apps (Visual Studio Community 2022 17.7.1)
    • Visual Studio at C:\Program Files\Microsoft Visual Studio\2022\Community
    • Visual Studio Community 2022 version 17.7.34009.444
    • Windows 10 SDK version 10.0.22621.0

[✓] Android Studio (version 2022.2)
    • 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 17.0.6+0-b2043.56-9586694)

[✓] VS Code (version 1.81.1)
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    • Flutter extension version 3.70.0

[✓] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.22621.2134]
    • Chrome (web)      • chrome  • web-javascript • unknown
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 115.0.1901.203

[✓] Network resources
    • All expected network resources are available.