sample.java

public class UserInfoFragment extends Fragment {
    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mViewModel = ViewModelProviders.of(getActivity()).get(UserInfoViewModel.class);

        mTvUserName.setText(mViewModel.getUserName());
        mTvWallet.setText(Formatter.formatCurrency(mViewModel.getWallet()));

        ArrayAdapter<String> adapter = new ArrayAdapter<>(
                getActivity(),
                android.R.layout.simple_spinner_item,
                mViewModel.getMonths()
        );
        adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);

        mSpExpenses.setAdapter(adapter);
        mSpExpenses.setOnItemClickListener((parent, view1, position, id) -> {
            String month = parent.getItemAtPosition(position).toString();
            mTvExpense.setText(mViewModel.getAmountOn(month, Transaction.EXPENSE_TYPE));
        });

        mSpIncome.setAdapter(adapter);
        mSpIncome.setOnItemClickListener((parent, view1, position, id) -> {
            String month = parent.getItemAtPosition(position).toString();
            mTvIncome.setText(mViewModel.getAmountOn(month, Transaction.INCOME_TYPE));
        });
    }
}

public class UserInfoViewModel extends AndroidViewModel {
    
    public UserInfoViewModel(Application app){
        super(app);
        AppDatabase database = AppDatabase.getInstance(app);
        mReports = database.getTransactionTable().getReports();
        mPref = new PreferenceManager(app);
    }
}