Gracefully handle IOException inside AsyncTask?

Question

How to gracefully display a Toast when an IOException occurs inside the doInBackground of an AsyncTask?

Answer 1

You can override either onPostExecute or onProgressUpdate to display messages on the UI thread.

To use onProgressDisplay declare the second type as String when you extend AsyncTask:

private class YourTask extends AsyncTask<ParamType, String, ReturnType> {

and override onProgressUpdate:

protected void onProgressUpdate(String... progress) {
     String errMsg = progress[0];
     Toast.makeText(getApplicationContext(), errMsg, Toast.LENGTH_SHORT).show();
}

then you can call the "progress" function when your exception occurs in doInBackground:

protected ReturnType doInBackground(ParamType... params) {
     try {
         // do stuff
     } catch (IOException e) {
        publishProgress("My Error Msg goes here");
     }
     return result;
 }