How to auto refresh webview after connecting to internet

Question

In my app I have implemented a webview to show an webpage conataing some useful information. Now Initially I checked whether Netwotk is available or not. If availbale it will connect to webpage. If not, it will show an alertdialog, telling that no internet connecttion on your device. After that it will redirect to setting option of device. I can swich on wifi from this option. But the problem is after turning on the wifi, when I go back to job page, it is not updated automatically. I have to go to my option menu page, then click on button and then it is updated. How can I update the page just after turning on the internet as like as google chrome. Here is my code for this

My Edited Code

    public class JobPage extends AppCompatActivity {

    private WebView webView;

    public static final String WIFI = "Wi-Fi";
    public static final String ANY = "Any";
    private static final String URL = "https://app.com";

    private static boolean wifiConnected = false;
    private static boolean mobileConnected = false;
    public static boolean refreshDisplay = true;

    public static String sPref = null;

    // The BroadcastReceiver that tracks network connectivity changes.
    private NetworkReceiver receiver = new NetworkReceiver();


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.job_layout);

        webView=(WebView)findViewById(R.id.webView);
       // Registers BroadcastReceiver to track network connection changes.
        IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        receiver = new NetworkReceiver();
        this.registerReceiver(receiver, filter);

    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        // Unregisters BroadcastReceiver when app is destroyed.
        if (receiver != null) {
            this.unregisterReceiver(receiver);
        }
    }
    // Refreshes the display if the network connection and the
    // pref settings allow it.


    // Checks the network connection and sets the wifiConnected and mobileConnected
    // variables accordingly.
    @Override
    public void onStart () {
        super.onStart();

        // Gets the user's network preference settings
        SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);

        // Retrieves a string value for the preferences. The second parameter
        // is the default value to use if a preference value is not found.
        sPref = sharedPrefs.getString("listPref", "Wi-Fi");

        updateConnectedFlags();

        if(refreshDisplay){
            loadPage();
        }
    }
    public void updateConnectedFlags() {
        ConnectivityManager connMgr = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo activeInfo = connMgr.getActiveNetworkInfo();
        if (activeInfo != null && activeInfo.isConnected()) {
            wifiConnected = activeInfo.getType() == ConnectivityManager.TYPE_WIFI;
            mobileConnected = activeInfo.getType() == ConnectivityManager.TYPE_MOBILE;
        } else {
            wifiConnected = false;
            mobileConnected = false;
        }
    }
    public void loadPage() {
        if (((sPref.equals(ANY)) && (wifiConnected || mobileConnected))
                || ((sPref.equals(WIFI)) && (wifiConnected))) {
            webView.loadUrl(URL);
            webView.getSettings().setJavaScriptEnabled(true);
            webView.setWebViewClient(new WebViewClient());
            refreshDisplay=true;

        } else {
            errorDialog();
        }
    }

    public void errorDialog(){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder
                .setMessage("No internet connection on your device. Would you like to enable it?")
                .setTitle("No Internet Connection")
                .setCancelable(false)
                .setPositiveButton("Enable Internet",
                        new DialogInterface.OnClickListener()
                        {
                            public void onClick(DialogInterface dialog, int id)
                            {
                                Intent dialogIntent = new Intent(android.provider.Settings.ACTION_SETTINGS);
                                dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                getApplicationContext().startActivity(dialogIntent);
                            }
                        });
        builder.setNegativeButton(" Cancel ", new DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int id)
            {
                dialog.cancel();
            }
        });

        AlertDialog alert = builder.create();
        alert.show();
    }

}

My NetworkReceiver Class

    public class NetworkReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        ConnectivityManager conn = (ConnectivityManager)
                context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = conn.getActiveNetworkInfo();

        // Checks the user prefs and the network connection. Based on the result, decides whether
        // to refresh the display or keep the current display.
        // If the userpref is Wi-Fi only, checks to see if the device has a Wi-Fi connection.
        if (WIFI.equals(sPref) && networkInfo != null && networkInfo.getType() == ConnectivityManager.TYPE_WIFI) {
            // If device has its Wi-Fi connection, sets refreshDisplay
            // to true. This causes the display to be refreshed when the user
            // returns to the app.

            Toast.makeText(context, "Wi-fi is connected", Toast.LENGTH_SHORT).show();
            JobPage.refreshDisplay = true;

            // If the setting is ANY network and there is a network connection
            // (which by process of elimination would be mobile), sets refreshDisplay to true.
        } else if (ANY.equals(sPref) && networkInfo != null) {
            JobPage.refreshDisplay = true;

            // Otherwise, the app can't download content--either because there is no network
            // connection (mobile or Wi-Fi), or because the pref setting is WIFI, and there
            // is no Wi-Fi connection.
            // Sets refreshDisplay to false.
        } else {
            JobPage.refreshDisplay = false;
            Toast.makeText(context, "Lost internet connection", Toast.LENGTH_SHORT).show();
        }
    }
}

Answer 1

You need to add a BroadcastReceiver for handling CONNECTIVITY_CHANGE. This will allow your app to be notified when the network status has changed, such as no internet to connected.

public class NetworkChangeReceiver extends BroadcastReceiver {

   @Override
   public void onReceive(final Context context, final Intent intent) {
       boolean isOnline = isOnline( context );
       // Fire an event with the new status of the network.
       Bus bus = new Bus(ThreadEnforcer.MAIN);
       bus.post( new NetworkEvent( isOnline ) );
   }

    public boolean isOnline(Context context) {
         ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
         NetworkInfo netInfo = cm.getActiveNetworkInfo();
         //should check null because in airplane mode it will be null
         return (netInfo != null && netInfo.isConnected());
     }
}

And there in your manifest, you also need to add that receiver.

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 <uses-permission android:name="android.permission.INTERNET" />
 <receiver
    android:name="NetworkChangeReceiver"
    android:label="NetworkChangeReceiver" >
    <intent-filter>
        <action android:name="android.net.wifi.WIFI_STATE_CHANGED" />
    </intent-filter>
</receiver>

Now, for actually sending the data, I'll use Otto, the event bus library.

Create a class to contain the information we'll be putting on the event bus.

public class NetworkEvent {

    private boolean isOnline;

    public NetworkEvent( boolean isOnline ) {
        this.isOnline = isOnline;
    }
}

And then finally in your JobPage activity, register ( and unregister on onDestroy ) the bus, and you can Subscribe to the event.

public class JobPage extends AppCompatActivity {
    @Override
    protected void onCreated( Bundle savedInstanceState ) {
        ...
        Bus bus = new Bus(ThreadEnforcer.MAIN);
        bus.register(this);
        ...
    }


    ...
    @Subscribe
    public void onNetworkChange( NetworkEvent event ) {
         if( event.isOnline ) {
            // Do refresh.
         }
    }
}

Answer 2

By Using Thread Handler you can run the web view after every 5 second please check below code .

  public class JobPage extends AppCompatActivity {

    private WebView webView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.job_layout);

        if(isNetworkStatusAvialable (getApplicationContext())) {
            Toast.makeText(getApplicationContext(), "internet available", Toast.LENGTH_SHORT).show();
            webView=(WebView)findViewById(R.id.webView);
            webView.loadUrl("https:...webaddress");
            webView.getSettings().setJavaScriptEnabled(true);
            webView.setWebViewClient(new WebViewClient());

            CallWebView();
        } else {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder
                    .setMessage("No internet connection on your device. Would you like to enable it?")
                    .setTitle("No Internet Connection")
                    .setCancelable(false)
                    .setPositiveButton("Enable Internet",
                            new DialogInterface.OnClickListener()
                            {
                                public void onClick(DialogInterface dialog, int id)
                                {
                                    Intent dialogIntent = new Intent(android.provider.Settings.ACTION_SETTINGS);
                                    dialogIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                                    getApplicationContext().startActivity(dialogIntent);
                                }
                            });
            builder.setNegativeButton(" Cancel ", new DialogInterface.OnClickListener()
            {
                public void onClick(DialogInterface dialog, int id)
                {
                    dialog.cancel();
                }
            });

            AlertDialog alert = builder.create();
            alert.show();
        }
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

    }

    public static boolean isNetworkStatusAvialable (Context context) {
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        if (connectivityManager != null)
        {
            NetworkInfo netInfos = connectivityManager.getActiveNetworkInfo();
            if(netInfos != null)
                if(netInfos.isConnected())
                    return true;
        }
        return false;
    }

    public void CallWebView() {
        final Handler ha=new Handler();
        ha.postDelayed(new Runnable() {

            @Override
            public void run() {
                //call function
                webView.loadUrl("http://www.google.com");
                ha.postDelayed(this, 1000);
            }
        }, 1000);
    }
}

Answer 3

Below code Will Call the methode after every 1 second so your webview will refresh after avery 1 second automatically

 public void CallWebView() {
        final Handler ha=new Handler();
        ha.postDelayed(new Runnable() {

            @Override
            public void run() {
                //call function
                 webView.loadUrl("http://www.google.com");
                ha.postDelayed(this, 1000);
            }
        }, 1000);
    }