Android Studio no access to internet

Question

My app to access a simple JSON and display it runs perfectly fine on the emulator(PIXEL 2 API 24) but not on any actual device I connect to it. Tried with both S8 and Note10, neither have data saver on either.

I even checked the apps data use afterwards and it said "0 B".

Here are the files:

MainActivity.java:

package com.example.internettest;

import androidx.appcompat.app.AppCompatActivity;

import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class MainActivity extends AppCompatActivity {

    Button button;
    TextView textView;
    ProgressDialog pd;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        button = (Button) findViewById(R.id.button);
        textView = (TextView) findViewById(R.id.textView);

        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new JsonTask().execute("http://46d30cf268b0.ngrok.io/LEATest/");
            }
        });
    }

    private class JsonTask extends AsyncTask<String, String, String> {
        protected void onPreExecute() {
            super.onPreExecute();



            //pd = new ProgressDialog(MainActivity.this);
            //pd.setMessage("Please wait");
            //pd.setCancelable(false);
            //pd.show();
        }

        protected String doInBackground(String... params) {


            HttpURLConnection connection = null;
            BufferedReader reader = null;

            try {
                URL url = new URL(params[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();


                InputStream stream = connection.getInputStream();

                reader = new BufferedReader(new InputStreamReader(stream));

                StringBuffer buffer = new StringBuffer();
                String line = "";

                while ((line = reader.readLine()) != null) {
                    buffer.append(line+"\n");
                    Log.d("Response: ", "> " + line);   //here u ll get whole response...... :-)
                }

                return buffer.toString();


            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (connection != null) {
                    connection.disconnect();
                }
                try {
                    if (reader != null) {
                        reader.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            //if (pd.isShowing()){
            //    pd.dismiss();
            //}
            Toast toast = Toast.makeText(getApplicationContext(),
                    "Before Try = |" + result + "|",
                    Toast.LENGTH_SHORT);

            toast.show();

            textView.setText(result);
        }
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.internettest">

    <uses-permission android:name="android.permission.INTERNET" />
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

Here's the result of pressing the button on the emulator(all fake username/passwords):

score 1 · Answer 1 · answered Aug 01 '20 at 05:35

Execure your JsonTask as follows -

new JsonTask().execute("https://46d30cf268b0.ngrok.io/LEATest/");

As suggested by @isthemartin, when you are running you app in actual device (S8 and Note10) the traffic is getting block because HTTP connection is not allowed.

Either you can add android:usesCleartextTraffic="true" but then you app will allow non secure HTTP connections.

I tried your API URL (https://46d30cf268b0.ngrok.io/LEATest/) is responding to the request so, why don't simply use it without making a security gap in your app.

score 0 · Answer 2 · answered Jul 31 '20 at 22:55

0

probably your actual devices are blocking http connections, so in this case you need to enable those connections, check this post

answered Jul 31 '20 at 22:55

isthemartin

96
8

score 0 · Answer 3 · answered Aug 01 '20 at 01:58

Please add this code to your AndroidManifest.xml file.

   android:usesCleartextTraffic="true"

so the code can be like this :

 <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.internettest">

<uses-permission android:name="android.permission.INTERNET" />
<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:usesCleartextTraffic="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

Android Studio no access to internet

3 Answers3