How to check internet connection continuously in Android Studio (Java) by using BroadcastReceiver

Step 1: Add Permissions to AndroidMenifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.ashish.checkinternetcontineously">
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <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/Theme.CheckInternetContineously">
        <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>

Step 2: Create resources file no_internet_connection.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="32dp"
        android:textColor="@color/black"
        android:textSize="20sp"
        android:textStyle="bold"
        android:text="OOPS!\nNo Internet Connection"
        android:gravity="center"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/btn_retry"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="24dp"
        android:text="Retry"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView" />
</androidx.constraintlayout.widget.ConstraintLayout>

Step 3: Create a package named "utility"

Step 4: Create a new class named "Common" inside the package "utility" and create a method "isConnectedToInternet" which returns the boolean data type.

package com.ashish.checkinternetcontineously.utils;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.Network;
import android.net.NetworkInfo;

public class Common {
    public static boolean isConnectedToInternet(Context context){
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);

        if (connectivityManager!= null){
            NetworkInfo[] info =  connectivityManager.getAllNetworkInfo();
            if (info!=null){
                for (NetworkInfo networkInfo : info) {
                    if (networkInfo.getState() == NetworkInfo.State.CONNECTED) {
                        return true;
                    }
                }
            }
        }
        return false;
    }
}

Step 5: Create a new class named "NetworkChangeListener" inside the package "utility" and extends the class by "BroadcastReceiver" and Override the "onReceive" method.

package com.ashish.checkinternetcontineously.utils;

import android.app.AlertDialog;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.View;
import androidx.appcompat.widget.AppCompatButton;
import com.ashish.checkinternetcontineously.R;

public class NetworkChangeListener extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if(!Common.isConnectedToInternet(context)){
            AlertDialog.Builder builder =  new AlertDialog.Builder(context);
            View view = LayoutInflater.from(context).inflate(R.layout.no_internet_connection,null);
            builder.setView(view);

            AppCompatButton btnRetry = view.findViewById(R.id.btn_retry);

            AlertDialog dialog = builder.create();
            dialog.show();
            dialog.setCancelable(false);
            dialog.getWindow().setGravity(Gravity.CENTER);

            btnRetry.setOnClickListener(view1 -> {
                dialog.dismiss();
                onReceive(context,intent);
            });
        }
    }
}

Step 6: We registered and unregistered the listener in "MainActivity.java"

package com.ashish.checkinternetcontineously;

import androidx.appcompat.app.AppCompatActivity;

import android.content.IntentFilter;
import android.net.ConnectivityManager;
import android.os.Bundle;

import com.ashish.checkinternetcontineously.utils.NetworkChangeListener;

public class MainActivity extends AppCompatActivity {

    NetworkChangeListener networkChangeListener = new NetworkChangeListener();
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    protected void onStart() {
        IntentFilter intentFilter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(networkChangeListener,intentFilter);
        super.onStart();
    }

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

Step 7: We have successfully created.

How to check internet connection continuously in Android Studio (Java) by using BroadcastReceiver