How to disable Mobile Data on Android?

This example demonstrates how do I disable Mobile data in Android.
For your find Information, unless you have a rooted phone I don't think you can enable and disable data programmatically because in order to do so we have to include MODIFY_PHONE_STATE permission which is only given to system or signature apps.
setMobileDataEnabled() method is no longer callable via reflection. It was callable since Android 2.1 (API 7) to Android 4.4 (API 19) via reflection, but as of Android 5.0 and later, even with the rooted phones, the setMobileDataEnabled() method is not callable.
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:orientation="vertical"
   android:padding="16dp"
   tools:context=".MainActivity">
   <Switch
      android:id="@+id/switchData"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:text="Mobile Data" />
</LinearLayout>
Step 3 − Add the following code to src/MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.content.Context;
import android.os.Bundle;
import android.telephony.TelephonyManager;
import android.util.Log;
import android.widget.CompoundButton;
import android.widget.Switch;
import java.lang.reflect.Method;
import java.util.Objects;
public class MainActivity extends AppCompatActivity {
   Switch mySwitch;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      mySwitch = findViewById(R.id.switchData);
      mySwitch.setChecked(getMobileDataState());
      mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
         @Override
         public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            setMobileDataState(isChecked);
         }
      });
   }
   public void setMobileDataState(boolean mobileDataEnabled) {
      try {
         TelephonyManager telephonyService = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
         Method setMobileDataEnabledMethod = Objects.requireNonNull(telephonyService).getClass().getDeclaredMethod("setDataEnabled", boolean.class);
         setMobileDataEnabledMethod.invoke(telephonyService, mobileDataEnabled);
      } catch (Exception ex) {
         Log.e("MainActivity", "Error setting mobile data state", ex);
      }
   }
   public boolean getMobileDataState() {
      try {
         TelephonyManager telephonyService = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
         Method getMobileDataEnabledMethod = Objects.requireNonNull(telephonyService).getClass().getDeclaredMethod("getDataEnabled");
         return (boolean) (Boolean) getMobileDataEnabledMethod.invoke(telephonyService);
      } catch (Exception ex) {
         Log.e("MainActivity", "Error getting mobile data state", ex);
      }
      return false;
   }
}
Step 4 − Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.sample">
   <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>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run   icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen −
Click here to download the project code