How to check internet availability in app | Android App Development | Java

 In this post, you will learn how to check the internet availability access in your application. Checking the internet access is important when working with API's, fetching or uploading data from servers etc...

Implementation:

First, in the activity_main.xml file, add the following code:

	<?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:id="@+id/refreshLayout"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	tools:context=".MainActivity">
	<Button
	android:id="@+id/newActivity"
	android:layout_width="0dp"
	android:layout_height="wrap_content"
	android:layout_marginStart="32dp"
	android:layout_marginEnd="32dp"
	android:text="New Activity"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintHorizontal_bias="0.5"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" />
	</androidx.constraintlayout.widget.ConstraintLayout>

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Then, create a new activity (NewActivity), and in its xml file (activity_new.xml), add the following code:

	<?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"
	tools:context=".NewActivity">
	<TextView
	android:id="@+id/textView"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="Network available"
	android:textSize="30sp"
	app:layout_constraintBottom_toBottomOf="parent"
	app:layout_constraintEnd_toEndOf="parent"
	app:layout_constraintHorizontal_bias="0.5"
	app:layout_constraintStart_toStartOf="parent"
	app:layout_constraintTop_toTopOf="parent" />
	<RelativeLayout
	android:id="@+id/networkLayout"
	android:layout_width="match_parent"
	android:layout_height="match_parent"
	android:visibility="gone">
	<ImageView
	android:id="@+id/img"
	android:layout_width="400dp"
	android:layout_height="400dp"
	android:layout_centerHorizontal="true"
	android:layout_marginTop="150dp"
	android:src="@drawable/no_network"/>
	<TextView
	android:layout_below="@+id/img"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:layout_centerHorizontal="true"
	android:textSize="40sp"
	android:text="No network..."/>
	</RelativeLayout>
	</androidx.constraintlayout.widget.ConstraintLayout>

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Now in the MainActivity.java file, add the onClickListener to the button to navigate to the NewActivity. To do this, add the following code:

	import android.content.Intent;
	import android.os.Bundle;
	import android.view.View;
	import android.widget.Button;
	import androidx.appcompat.app.AppCompatActivity;
	public class MainActivity extends AppCompatActivity {
	Button newActivityButton;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	newActivityButton = findViewById(R.id.newActivity);
	newActivityButton.setOnClickListener(new View.OnClickListener() {
	@Override
	public void onClick(View view) {
	startActivity(new Intent(MainActivity.this, NewActivity.class));
	}
	});
	}
	}

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After this, create a new Java class to check the network state. In this class (CheckNetwork.java), add the following code:

	import android.content.Context;
	import android.net.ConnectivityManager;
	import android.net.NetworkInfo;
	public class CheckNetwork {
	public static boolean isInternetAvailable(Context context){
	NetworkInfo info = (NetworkInfo)((ConnectivityManager)
	context.getSystemService(Context.CONNECTIVITY_SERVICE)).getActiveNetworkInfo();
	if (info==null){
	return false;
	}
	else{
	if(info.isConnected()){
	return true;
	}
	else{
	//Internet connection available
	return true;
	}
	}
	}
	}

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Now, in the NewActivity.java file, add the following code:

	import androidx.appcompat.app.AppCompatActivity;
	import android.os.Bundle;
	import android.view.View;
	import android.widget.RelativeLayout;
	import android.widget.TextView;
	public class NewActivity extends AppCompatActivity {
	RelativeLayout relativeLayout;
	TextView txt;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_new);
	relativeLayout = findViewById(R.id.networkLayout);
	txt = findViewById(R.id.textView);
	if(CheckNetwork.isInternetAvailable(this)){
	relativeLayout.setVisibility(View.GONE);
	txt.setVisibility(View.VISIBLE);
	}else{
	relativeLayout.setVisibility(View.VISIBLE);
	txt.setVisibility(View.GONE);
	}
	}
	}

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Finally, add the Internet and Access Network State permissions in the AndroidManifest.xml file

	<uses-permission android:name="android.permission.INTERNET"/>
	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

view raw xml hosted with ❤ by GitHub

And that's it...Now try running your app. To learn more about reading the Network States in Android, refer this : https://developer.android.com/training/basics/network-ops/reading-network-state?authuser=1

Happy Learning... :-)