How to return ArrayList from AsyncTask to another class?

Question

i want to get Ftp folders list from server using AsyncTask and return folders names ArrayList to main class and update spinner adapter.

In main class i got spinner with

Answer 1

Implement a listener passing ArrayList and use this listener for returning your ArrayList.

public interface TaskListener {
    public void onSuccess(ArrayList result);

}

While invoking your async task for operation execution create an instance of TaskListener as follows:

TaskListener listener = new TaskListener() {

        @Override
        public void onSuccess(ArrayList result) {
               // Your result will come here
        }
    };

Pass this listenerobject as a parameter to the async task constructor. And create a global instance of TaskListener in the async task itself. Assign the TaskListener parameter in the constructor to the global instance.

Then in the onPostExecute of the async task class:

protected ArrayList[] onPostExecute(ArrayList... result) {
        this.taskListenerGlobalInstance(result); // this will invoke the call back method 

    }