Android BroadcastReceiver Example

1/  Create A Class MyReceiver class and extends BroadcastReceiver Check Internet Connectivity

package com.example.androideample;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;

import android.util.Log;
import android.widget.Toast;

public class MyReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {


        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        boolean isConnected = netInfo != null && netInfo.isConnected();

        if (isConnected) {
            Toast.makeText(context, "Internet connected", Toast.LENGTH_SHORT).show();
            Log.i("NetworkChangeReceiver", "Internet connected");

        } else {
            Toast.makeText(context, "No internet connection", Toast.LENGTH_SHORT).show();
            Log.i("NetworkChangeReceiver", "No internet connection");

        }
    }

}

package com.example.androideample;

import androidx.appcompat.app.AppCompatActivity;
import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.os.Bundle;


public class MainActivity extends AppCompatActivity {
    MyReceiver myReceiver = new MyReceiver();
    IntentFilter intentFilter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        intentFilter=new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(myReceiver, intentFilter);

    }


    @Override
    protected void onStop() {
        super.onStop();
        unregisterReceiver(myReceiver);
    }
}

3/ Then Change AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AndroidEample">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        
        <receiver android:name="MyReceiver" 
            android:exported="true">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>

        </receiver>


    </application>

    

</manifest>