Why is ArrayAdapter always null in this example?

Question

I have a code structured as follows:

public class MyListFragment extends ListFragment {
    private ArrayList<User> users;

    private void initAdapter() {
        if(users == null) return;
        //getUserStatus(users); <———HERE 1
        UsersAdapter adapter = new UsersAdapter(users);
        setListAdapter(users);
        getUserStatus(users);   // vs <—— HERE 2
    }  

    private void getUserStatus(List<User> users) {
        final UsersAdapter  adapter = (UsersAdapter )getListAdapter();
                 for(User user:users) {
            Thread t = new Thread(new Runnable() {
                //code to fetch some data
                if ( adapter == null) Log.e(“App”, “Adapter is NULL!”);
            });
            t.start();
        }
    }

    private UsersAdapter extends ArrayAdapter<User> {
        public UsersAdapter(List<User> users) {
            super(getActivity(), 0, users);
        }

        @Override
                public View getView(int position, View convertView, ViewGroup parent) {
            //code to inflate and populate list item
        }       
    }   

My question is:
Why if in my initAdapter if I comment out getUserStatus in the current version marked as HERE 2 and uncomment HERE 1 so that getUserStatus is run before setListAdapter the adapter is always null in getUserStatus? I always see in the logs by all threads Adapter is NULL?

Answer 1

It's simple. In HERE 1, you are trying to get the user related things from adapter you haven't initialized yet which is inialising using the function setListAdapters(users). In HERE 2, you are getting the users after initialising adapters, so it is working fine.