Check internet in background - Android

Question

I have been doing some research and seen some debate of whether to use Broadcast Receiver or Alarm Manager, Im not sure what to use but here is what I am trying to do and have done.

I have a method that will check if there is internet connection. And then updates the UI accordingly.

public void isNetworkAvailable() {
    ConnectivityManager manager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = manager.getActiveNetworkInfo();

    if (networkInfo != null && networkInfo.isConnected()) {
        mLayout.removeView(noInternetView);
        checkInternetViewOpen = false;
    } else {
        if (!checkInternetViewOpen) {
            checkInternetViewOpen = true;
            mLayout.addView(noInternetView, params);
        }
    }
}

And while I am in an activity that will be using the internet I want to run this once every few seconds to make sure the internet is still active. Like this

while (usingInternet) {
    //I need to make it wait
    isNetworkAvailable();

}

I also need to be not on the main thread for this, so I can make it wait, and then I will adjust the updating the UI parts on the main tread.

So how can I make this on a background thread? And what option should I use?

Thanks for the help in advance.

Answer 1

As I understand you want to check Internet connection and if connected then you have to perform certain operations either in backgroung or on UI thread.

So I suggest you to write Broadcast reciever for connection changes and a Service class if connected start the Service.

In that service write A TimerTask that will run after some specific period. In TimerTask you write data on shared pref and when user opens Application you can update UI from shared data

Answer 2

You can create a background thread to check for this task. Here are my sample code.

The only things left for you to do is to fulfill setNetworkAvaiableUI(), setNetworkNotAvaiableUI(), and set NETWORK_CHECK_INTERVAL.

private boolean isCheckNetworkThreadActive = false; // Flag to indicate if thread is active
private boolean isNetworkAvaiableUIActive = false; // Flag to indicate which view is showing
final private static int NETWORK_CHECK_INTERVAL = 5000; // Sleep interval between checking network

@Override
protected void onResume() {
    // Start network checking when activity resumes
    startCheckNetwork();
    super.onResume();
}

@Override
protected void onPause() {
    // Stop network checking when activity pauses
    stopCheckNetwork()
    super.onPause();
}

private void setNetworkAvaiableUI() {
    // If network avaible UI is not showing, we will change UI
    if (!isNetworkAvaiableUIActive) {
        isNetworkAvaiableUIActive = true;
        runOnUiThread(new Runnable() {
            public void run() {
                // Update UI here when network is available.
            }
        });
    }
}
private void setNetworkNotAvaiableUI() {
    // If network avaible UI is showing, we will change UI
    if (isNetworkAvaiableUIActive) {
        isNetworkAvaiableUIActive = false;
        runOnUiThread(new Runnable() {
            public void run() {
                // Update UI here when network is unavailable.
            }
        });
    }
}

private void startCheckNetwork() {
    // Only one network checking thread can be run at the time.
    if (!isCheckNetworkThreadActive) {
        isCheckNetworkThreadActive = true;

        Thread checkNetworkThread = new Thread(new Runnable() {
            @Override
            public void run() {
                while (isCheckNetworkThreadActive) {
                    if (isNetworkAvailable()) {
                        // Set UI if notwork is available
                        setNetworkAvaiableUI();
                    } else {
                        // Set UI if notwork is not available
                        setNetworkNotAvaiableUI();
                    }

                    // Sleep after finish checking network
                    try {
                        Thread.sleep(NETWORK_CHECK_INTERVAL);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
        checkNetworkThread.setName("Check Network Thread");
        checkNetworkThread.start();
    }
}

private void stopCheckNetwork() {
    // This will break while loop of network checking thread.
    isCheckNetworkThreadActive = false;
}

You can also make the code a lot shorter by using Timer and Handler, that are the options.

Answer 3

Case 1: Check internet status throughout the app

Extend the Application class and add a broadcast receiver in it.

public class MyApplication extends Application {

public static boolean isConnected = false;
/**
 * To receive change in network state
 */
private BroadcastReceiver NetworkStatusReceiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {

        ConnectivityManager connMgr = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();

        isConnected = networkInfo != null && networkInfo.isConnectedOrConnecting();

        if (!isConnected) {
            Toast noInternetToast = Toast.makeText(getApplicationContext(),
                    R.string.no_internet_msg, Toast.LENGTH_LONG);
            noInternetToast.show();
        }
    }
};

@Override
public void onCreate() {
    super.onCreate();
    /** Register for CONNECTIVITY_ACTION broadcasts */
    registerReceiver(NetworkStatusReceiver, new IntentFilter(
            ConnectivityManager.CONNECTIVITY_ACTION));
}

@Override
public void onTerminate() {
    super.onTerminate();
    unregisterReceiver(NetworkStatusReceiver);
}
}

In app's AndroidManifest.xml

<application
    android:name=".MyApplication"
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
</application>

At any place in your app, you may check internet like

if(MyApplication.isConnected){
   /** Do your network operation **/
}

Case 2: Within an activity or fragment

Just add the broadcast receiver in each activity or fragment that needs internet status.