Why is my object not being set in AsyncTask?

Issue

I call a AsyncTask method to retrieve a entry from my room database. I do this in an AsyncTask as to not block the UI thread. In my doInBackGround method I assign a value to the object and we can see here it gets set:

On my post execute I call a method which uses this object. But it assigns as null and the program fails.

How come this value that I assigned in doInBackground didn't persist when I want to access in another method?

AsyncTask

 void getAtcUser(String username) {

    new getAtcUserAsyncTask(username).execute();
}

private class getAtcUserAsyncTask extends AsyncTask<Void, Void, Void> {
   String name;


    getAtcUserAsyncTask(String name) {
        this.name = name;
    }

    @Override
    protected Void doInBackground(Void... params) {
        atcUserStats = mAtcDao.findByName(name);
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        ATC_GameOver atc_gameOver = new ATC_GameOver();
        atc_gameOver.callOnChanged();
    }
}

Retrieve assigned value

public AtcUserStats getAtcUserStats(){
    return atcUserStats;
}

callOnChanged

public void callOnChanged() {


    mRepository = new UsersRepository(getApplication());
    AtcUser = mRepository.getAtcUserStats(); //Assgins null here - then program fails when I try access this object on the next line
    int singlesPlayed = AtcUser.getSinglesPlayed();

The error I am getting is a null object reference but how when I've assigned it previously? Is there a better way of doing this?

Solution

Manged to get it working. Rather than retrieving it in callOnChanged I passed it as a parameter to callOnChanged on post-execute and AtcUser was no longer null.

AsyncTask

 private class getAtcUserAsyncTask extends AsyncTask<Void, Void, Void> {
   String name;


    getAtcUserAsyncTask(String name) {
        this.name = name;
    }

    @Override
    protected Void doInBackground(Void... params) {
        setAtcUserStats(mAtcDao.findByName(name));
        return null;
    }

    @Override
    protected void onPostExecute(Void aVoid) {
        super.onPostExecute(aVoid);
        ATC_GameOver atc_gameOver = new ATC_GameOver();
        atc_gameOver.callOnChanged(atcUserStats);
    }
}

private void setAtcUserStats(AtcUserStats byName) {
    atcUserStats = byName;
}

callOnChanged

public void callOnChanged(AtcUserStats atc_user) {


    mRepository = new UsersRepository(app);
    AtcUser = atc_user;

Answered By - COYG