Problems with AsyncTask?

Question

I'm trying to understand the AsyncTask class, I wrote a simple code which computes if a number is Prime in a not optimized way. I don't want to compute the prime problem in the main thread, so I implemented the following class:

private class PrimeTask extends AsyncTask<Integer, Void, String>{
    public String isPrime(Integer n){
        for(int i=2; i<n-1; i++){
            if(n%i==0){
                return "Not Prime";
            }
        }
        return "Is Prime";
    }
    @Override
    protected String doInBackground(Integer ... num){
        return isPrime(num[0]);
    }
    @Override
    protected void onPostExecute(String result){
        output.setText(result);
    }
}

I compute this task every time the user presses the button in the MainActivity.

        output = findViewById(R.id.Ouput);

    myButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            EditText input = findViewById(R.id.Input);
            //output.setText(isPrime(Integer.parseInt(input.getText().toString())));
            PrimeTask task = new PrimeTask();
            task.execute(Integer.parseInt(input.getText().toString()));
        }
    });

but when I run the application I still get the following message!

I/Choreographer: Skipped 57 frames!  The application may be doing too much work on its main thread

Why do I still have this message? Am I doing anything wrong?

Possible duplicate of [The application may be doing too much work on its main thread](https://stackoverflow.com/questions/14678593/the-application-may-be-doing-too-much-work-on-its-main-thread) — AskNilesh, Jan 03 '18 at 13:32
You are using the async task in a wrong way, it is meant to be for long running tasks that require disk I/0, network operations etc. Also you don't have to findViewById(R.id.Input); every time user clicks the button, initialize it in onCreate(). — Muhammad Babar, Jan 03 '18 at 13:32
@MuhammadBabar no, he can use it for this task as well, that is not the problem. concerning calling findViewById in onClick you are right! — Willi Mentzel, Jan 03 '18 at 13:41
@Hamall: This might help https://stackoverflow.com/a/32295725/1788806 The way you use AsyncTask is correct — Willi Mentzel, Jan 03 '18 at 13:43
@Hamali Are you sure this is the piece of code which is causing this ? — gvmani, Jan 03 '18 at 13:43
@gvmani there is not other code, only the onCreate() method in MainActivity. — Hamall, Jan 03 '18 at 13:54
@MuhammadBabar I put the "findViewById(R.id.Input)" in onCreate, now there are two messages saying: Main Thread has too much work! — Hamall, Jan 03 '18 at 14:02
@MuhammadBabar, the code inside onCreate can also cause, if you are doing something there. You might have to strip your code and see if it goes away. Else try this [https://stackoverflow.com/a/32295725/1825844] — gvmani, Jan 03 '18 at 14:08

Problems with AsyncTask?

0 Answers0