Develop Reference

Error on any react native http call (android only

I'm developing a react native app using expo.
In IOS everything works perfectly, however in Android, any http call returns an error.
In my case, I use axios, so I only have a NETWORK ERROR, without further details, but even when fetching values ​​from remoteConfig I get an error.
The API is already published.
Does anyone have any suggestions?
Axios error
i hope the request works

Did you had the related permissions in the AndroidManifest ?
In the file android -> app -> src -> main -> AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.YOUR_APP_NAME">
<uses-permission android:name="android.permission.INTERNET" /> //This line
<application ... >
...
</application>
</manifest>

How do I deal with the Agora exception "e/agora sdk cannot open log file for writing agorartm.log err=30"?

I use Agora as my RTM(Real Time Messaging) SDK, but after I set it up for Android develop, everything worked fine except for the problem that the RTMClientListener did not automatically update the messages received, and the debug console shows "e/agora sdk cannot open log file for writing agorartm.log err=30". Does anyone know how to fix this? Thanks in advance.

Try this:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
The lines above allow Android application read and write permission of external files Add this into AndroidManifest.xml file - before application tag:
package="com.example.yourproject">
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<application...
Regarding the Agora Flutter app, the example app only works with low security mode Agora projects. Token or primary certificate activated projects won't work with the example app. Go to Agora dashboard, create a new project with low security level - only APP Id type. Then try the example app with the new App id copied from the dashboard of new project.

Network Error on API requests on Expo Android

I am developing a React Native app using Expo and I recently ran into a weird issue. API requests don't work on Android devices however they're totally fine on iOS. The server I'm trying to connect to isn't localhost. I tried to use axios and fetch, both result in Network Error and the server doesn't receive a request. I also made requests to open APIs which got me the same error, so I believe the problem isn't on the server's side.
Here's the code of the request:
const axiosInstance = axios.create({
timeout: 120000,
headers: {
'Accept': 'application/json',
'Content-Type': 'application/json',
'Access-Control-Allow-Origin': '*'
}
})
const res = await axiosInstance.post(`${serverHostApi}/merchant/login`, payload)
Here's the stack trace:
Network Error
- node_modules\axios\lib\helpers\normalizeHeaderName.js:8:14 in processHeader
* http://192.168.150.71:19001/node_modules%5Cexpo%5CAppEntry.bundle?platform=android&dev=true&minify=false&hot=false:226876:26 in handleError
- node_modules\event-target-shim\dist\event-target-shim.js:818:20 in EventTarget.prototype.dispatchEvent
- node_modules\react-native\Libraries\Network\XMLHttpRequest.js:575:10 in setReadyState
- node_modules\react-native\Libraries\Network\XMLHttpRequest.js:389:6 in __didCompleteResponse
- node_modules\react-native\Libraries\vendor\emitter\EventEmitter.js:189:10 in emit
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:425:19 in __callFunction
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:112:6 in __guard$argument_0
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:373:10 in __guard
- node_modules\react-native\Libraries\BatchedBridge\MessageQueue.js:111:4 in callFunctionReturnFlushedQueue
* [native code]:null in callFunctionReturnFlushedQueue
I'm using Expo 38.0.0, React Native SDK 38.0.2.
Any help would be highly appreciated!

If this is happening only in the android app. It might be a case you accidently removed internet permission from your android app. Kindly check you have proper permission in the Android Manifest File.
To Check , go the YourApp/android/app/src/main and open AndroidManifest.xml
and check if you have this line
<uses-permission android:name="android.permission.INTERNET" />
if you don't have it , add this line inside your Manifest file like this
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.INTERNET" />
</manifest>

I also ran into this problem.
You can use tools like SSL Labs to test the validity of your SSL certificate.
SSL SERVER TEST
I solved it with this method

Only way that I found to resolve is downgrade the version. Or you should make sure that TLS 1.0 and TLS 1.1 is disabled on the server.
"axios": "0.24.0"

Flutter APK Build

Goo day friends! I am new to Flutter and I have been experimenting on fetching data via REST API. On Android Studio, everything works just fine, so I suppose there's nothing wrong with my code.
Things I did to make sure my code works:
1.) Run the code in android simulator;
2.) Run the code using real device (enabling USB Debugging).
And it works just fine.
But when I build an apk file out of it and install it on my device, it no longer makes the API call (or is unable to?). I made it so, when the app runs initState(), it waits for the data to be loaded. While the data is not yet available, a CircularProgressIndicator() takes the entire screen.
If I run the app via the installed apk file, it's just CircularProgressIndicator(). Meaning, no data is being loaded and displayed. But when I run the code in AndroidStudio, the data is shown..
I am using http package. I'm not sure what I'm doing wrong, or what I'm missing.
Other things to note: I did not change anything in my AndroidManifest file, and just followed all the steps on building apk file in Flutter through the official documentation.

Like alexsanderfr said, this is indeed most of the time being caused by missing
<uses-permission android:name="android.permission.INTERNET" />
You shouldn't need
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
for REST API.
In Flutter, when debugging you implicitly have access to internet, however in release builds, you need to explicitly declare this permission.
update1
Ensure you have the http-package added to your pubspec.yaml file and that it's properly indented with two spaces:
dependencies:
flutter:
sdk: flutter
cupertino_icons: ^0.1.2
http: ^0.12.0+4

Did you add the internet permission to the manifest? If you're accessing the internet from an Android app you need to add the internet permission over the application tag.
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />

Connecting localhost via android - Connection to 10.0.2.2 refused

I have an apache server installed in my PC where I host one PHP file.
Then I tried to connect to that file using eclipse, but it always gives me below error
connection to http://10.0.2.2:8080 refused.
I tried changing address to the followings, but got similar error all the time.
http://10.0.2.2
http://127.0.0.1
http://localhost
Can anyone please help me.
EDITED: Just for information, I can access to remoter server (e.g. www.mydomain.com) without any problem.
CLASS FILE:
HttpClient httpclient = new DefaultHttpClient();
Log.d("test","t0");
HttpPost httppost = new HttpPost("http://10.0.2.2:8080/mylibman/data.php");
Log.d("test","t1");
HttpResponse response = httpclient.execute(httppost); // error here
Log.d("test","t2");
Android Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.migrationdesk.mylibman"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="18" />
<uses-permission android:name="android.permission.INTERNET" />
Error LogCat:
11-16 02:02:20.803: E/log_tag(1427): Error in http connection org.apache.http.conn.HttpHostConnectException: Connection to http://10.0.2.2:8080 refused
11-16 02:02:20.803: E/log_tag(1427): Error converting result java.lang.NullPointerException: lock == null
11-16 02:02:20.803: E/log_tag(1427): Error parsing data org.json.JSONException: End of input at character 0 of

alright go to Apache httpd.conf (located in Apache folder): and search for
Order Deny,Allow
Deny from all
Allow from 127.0.0.1
and check if the second line is Deny, if it is then change it to:
Allow from all
then restart the Appache server, and tell me the feadback.
Edit
try it out in your real device:
go to CMD and type ipconfig under IPv4 take the IP address and change the IP it will look similar to this:
http://192.168.0.106:8080/mylibman/data.php // similar to this.
Turn Off the firewall and any anti-virus application in your PC
and please give me the feedback.

Mike helped me a lot on this issue. So here my steps to avoid this Connection refused.
1) Add if to test Android SDK. It seems that in new versions you have to explicity allow the connection to be open in a different thread:
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
System.out.println("*** My thread is now configured to allow connection");
}
...
2) Add an exception for your port:
in your case allow inbound connection for port 8080
3) test your connection by browsing the desired url locally
use your browser and try to visit http://10.0.2.2:8080 locally
4) Add in your manifest file a permission for internet:
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.yourapp"
android:versionCode="1"
android:versionName="1.1" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="19" />
<uses-permission android:name="android.permission.INTERNET"/>
I am using Wamp, and its apache is listening to servername localhost and port 8080 (allow from all in httpd.conf).
My local IP is something similar to 192.168.0.XXX/folder/my-page-here

You can use your real IP address to reach your virtual server. Take a look at my answer here. I hope it helps.

if your SDK version is less then 9 then add above code for SDK version them some changes in Apache update httpd.conf as line deny from all..replace that sentence Allow from all and restart services of WAMP server then use 10.0.2.2 address or 10.0.2.2:8080 port no and include permission line in android AndroidManifest file
<uses-permission
android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE">
</uses-permission>

I fix this problem by writing my IP address from cmd -> ipconfig in the url :
HttpPost httppost = new HttpPost( "http://192.168.x.x/mylibman/data.php" );