How can I create AsyncTask of my getTotalIncomeAmount() which is an Integer type function in my IncomeDao class

Question

I want to get total income amount from my Income table which have Amount table

 @ColumnInfo(name = "Amount")
    private int amount;

And in my IncomeDao I've

 @Query("SELECT SUM(amount) from income_table")
    Integer getTotalIncomeAmount();

And in my IncomeRepository I've

public Integer getTotalIncomeAmount()
    {

        return incomeDao.getTotalIncomeAmount();
    }

In my IncomeViewModel

public Integer getTotalIncomeAmount()
    {
        return incomeRepository.getTotalIncomeAmount();
    }

And I call this in my Main thread like this

totalIncome = incomeViewModel.getTotalIncomeAmount();

But it gives me the error that 'Cannot access database on the main thread since it may potentially lock the UI for a long period of time.'

I know this error can be remove by creating LiveData<Integer> getTotalIncomeAmount(). But I don't want to do this by LiveData because I've to observe it which is not good in my case.

I want someone to show me how to create AsyncTask of this method in my IncomeRepositoryclass because I know this is the only way to get rid of this error. I'm fairly new in programming. As I created other AsyncTask like this in my IncomeRepository

private static class UpdateIncomeAsyncTask extends AsyncTask<Income, Void, Void>
    {
        private IncomeDao incomeDao;
        private UpdateIncomeAsyncTask(IncomeDao incomeDao)
        {
            this.incomeDao = incomeDao;
        }

        @Override
        protected Void doInBackground(Income... incomes)
        {
            incomeDao.update(incomes[0]);
            return null;
        }
    }

I just need someone to complete private static class TotalIncomeAmountAsyncTask extends AsyncTask<Void, Void, Void> for me. I tried very hard but I could succeed. Thanks in advance

Answer 1

Try below code,

You will get amount in doInBackgroud method from database, after geting value you will get call in onPostExecute method. If you have global variable then you can directly set value in doInBackgroud method.

private void getTotalIncomeAmount() {
        class TotalIncomeAmountAsyncTask extends AsyncTask<Void, Void, Integer> {

            @Override
            protected Integer doInBackground(Void... voids) {
             
                Integer value = DatabaseClient.getInstance(getApplicationContext()).getAppDatabase()
                        .taskDao()
                        .getTotalIncomeAmount();
                return value;
            }

            @Override
            protected void onPostExecute(Integer value) {
                super.onPostExecute(value);
                //
            }
        }
        TotalIncomeAmountAsyncTask totalIncome = new TotalIncomeAmountAsyncTask();
        totalIncome.execute();
    }