How to Check Internet Connection and Show an Alert Dialog in Android

Detecting Internet Connection and Show an Alert Dialog in Android

Step-1:
Create a class like ConnectionDetector.java
package bd.base.mamun.tabsswipe;

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

public class ConnectionDetector {
   
    private Context _context;
   
    public ConnectionDetector(Context context){
        this._context = context;
    }

    public boolean isConnectingToInternet(){
        ConnectivityManager connectivity = (ConnectivityManager) _context.getSystemService(Context.CONNECTIVITY_SERVICE);
          if (connectivity != null)
          {
              NetworkInfo[] info = connectivity.getAllNetworkInfo();
              if (info != null)
                  for (int i = 0; i < info.length; i++)
                      if (info[i].getState() == NetworkInfo.State.CONNECTED)
                      {
                          return true;
                      }

          }
          return false;
    }
}

Step-2 : 

public class ComingSoonActivity extends Activity {
 // flag for Internet connection status
                Boolean isInternetPresent = false;
                // Connection detector class
                ConnectionDetector cd;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_coming_soon);
        cd = new ConnectionDetector(getApplicationContext());
        isInternetPresent = cd.isConnectingToInternet();
 
if(!isInternetPresent){   
           
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            builder.setCancelable(false);
            builder.setTitle(Html.fromHtml("<font color='#7F02AE'>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<b>Star Cineplex</b></font>"));
            builder.setMessage(Html.fromHtml("<font color='#120049'>Your data services are not working.Please check your data services.</font>"));
            builder.setPositiveButton(Html.fromHtml("<font color='#7F02AE'><b>OK</b></font>"), new DialogInterface.OnClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which) {

                  Intent intent = new Intent(Intent.ACTION_MAIN);
                  intent.addCategory(Intent.CATEGORY_HOME);
                  intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP 
                  startActivity(intent);                         
                  finish();
               
                  
                   
                }
            });

          /*  builder.setNegativeButton("No",new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    //if user select "No", just cancel this dialog and continue with app
                    dialog.cancel();
                }
            });*/

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

    } 
 

}

To Get: