how to check internet connection in android

ConnectionDetector.java

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;
    }
}

AlertDialogManager.java

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;

public class AlertDialogManager {

    @SuppressWarnings("deprecation")
    public void showAlertDialog(Context context, String title, String message,
            Boolean status) {
        AlertDialog alertDialog = new AlertDialog.Builder(context).create();

        // Setting Dialog Title
        alertDialog.setTitle(title);

        // Setting Dialog Message
        alertDialog.setMessage(message);

        if (status != null)
            // Setting alert dialog icon
            alertDialog.setIcon((status) ? R.drawable.ic_launcher
                    : R.drawable.ic_launcher);

        // Setting OK Button
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {

                // finish();

                dialog.cancel();

            }
        });

        // Showing Alert Message
        alertDialog.show();
    }
}

MainActivity.java

public class MainActivity extends Activity {

    public static Context con;
    static ConnectionDetector cd;
    static AlertDialogManager alert = new AlertDialogManager();

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

         con = MainActivity.this;

         cd = new ConnectionDetector(getApplicationContext());

        if (!cd.isConnectingToInternet()) {

            alert.showAlertDialog(con, "Internet Connection Error","Please connect to working Internet connection", false);

        } else {
                           -----your operation-----
        }

}