Display an alert when internet connection not available in android application

Question

In my application data comes from internet and I am trying to create a function that checks if a internet connection is available or not and if it isn't, it gives an alert messege that no internet connection available. i am using following code. but its not working.

public void onCreate(Bundle savedInstanceState){
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main1);
  if (isOnline())
  {
   // my code
  }
  else
  {
   Hotgames4meActivity1.this.startActivity(new Intent(Settings.ACTION_WIRELESS_SETTINGS)); 
    try {
       AlertDialog alertDialog = new AlertDialog.Builder(Hotgames4meActivity1.this).create();

       alertDialog.setTitle("Info");
       alertDialog.setMessage("Internet not available, Cross check your internet connectivity and try again");
       //alertDialog.setIcon(R.drawable.alerticon);
       alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
         public void onClick(DialogInterface dialog, int which) {
          finish();

         }
       });

       alertDialog.show();
    }
    catch(Exception e)
    {
       //Log.d(Constants.TAG, "Show Dialog: "+e.getMessage());
    }
  }
}

Answer 1

public boolean isOnline() {
    ConnectivityManager conMgr = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo netInfo = conMgr.getActiveNetworkInfo();

    if(netInfo == null || !netInfo.isConnected() || !netInfo.isAvailable()){
        Toast.makeText(context, "No Internet connection!", Toast.LENGTH_LONG).show();
        return false;
    }
return true; 
}

And you must add premission for accessing network state and Internet:

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