What is the best practice to use nested AsyncTasks?

Question

In my Android app I have up to 4 asynchronous tasks that depend on each other, which means that one task has to finish before the next one can go one with the retreived data. Now this can be quite unclear at some point when the code looks something like this:

final AsyncTask<Void, Void, Boolean> taskOne = new AsyncTask<Void, Void, Boolean>() {   
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected Boolean doInBackground(Void... params) {
        // retrieve required data   
        return true;
    }

    @Override
    protected void onPostExecute(Boolean success) {
        if (success) {
            // start second task here
            final AsyncTask<Void, Void, Boolean> taskTwo = new AsyncTask<Void, Void, Boolean>() {
                @Override
                protected void onPreExecute() {
                    super.onPreExecute();
                }

                @Override
                protected Boolean doInBackground(Void... params) {
                    // retrieve required data   
                    return true;
                }

                protected void onPostExecute(Boolean success) {
                    if (success) {
                        // start third task here
                        final AsyncTask<Void, Void, Boolean> taskThree = new AsyncTask<Void, Void, Boolean>() {
                            @Override
                            protected void onPreExecute() {
                                super.onPreExecute();
                            }

                            @Override
                            protected Boolean doInBackground(Void... params) {
                                // retrieve required data   
                                return true;
                            }

                            protected void onPostExecute(Boolean success) {
                                if (success) {
                                    // and so on ...
                                }
                            }
                        }

                        taskThree.execute();
                    }
                }
            }

            taskTwo.execute();
        }
    }
}

taskOne.execute();

What would be the best practice to achieve this behaviour with a more readable code?

Thanks in advance

Answer 1

TaskOne

Class TaskOne extends AsyncTask{

  onPostExecute(boolean success){
     if(success){
        new TaskTwo().execute();
     }
  }
}

TaskTwo

Class TaskTwo extends AsyncTask{

  onPostExecute(boolean success){
     if(success){
        new TaskThree().execute();
     }
  }
}

TaskThree

Class TaskThree extends AsyncTask{

      onPostExecute(boolean success){
         if(success){
            //do something
         }
      }
}