RoomDB和AsyncTask

Question

当我尝试使用房间显示来自数据库sqllite的日期的RecyclerView时出现错误。但是我不知道为什么这个错误不会在任何时候出现。

E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #1
              Process: corporate.foody.it.myapplication, PID: 20161
              java.lang.RuntimeException: An error occurred while executing doInBackground()
                  at android.os.AsyncTask$3.done(AsyncTask.java:353)
                  at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:383)
                  at java.util.concurrent.FutureTask.setException(FutureTask.java:252)
                  at java.util.concurrent.FutureTask.run(FutureTask.java:271)
                  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245)
                  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
                  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
                  at java.lang.Thread.run(Thread.java:764)
               Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
                  at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:7313)
                  at android.view.ViewRootImpl.requestLayout(ViewRootImpl.java:1161)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.support.constraint.ConstraintLayout.requestLayout(ConstraintLayout.java:3172)
                  at android.view.View.requestLayout(View.java:21995)
                  at android.support.v7.widget.RecyclerView.requestLayout(RecyclerView.java:4090)
                  at android.support.v7.widget.RecyclerView.setAdapter(RecyclerView.java:1085)
                  at corporate.foody.it.myapplication.RistoranteFragment$1.doInBackground(RistoranteFragment.java:75)
                  at corporate.foody.it.myapplication.RistoranteFragment$1.doInBackground(RistoranteFragment.java:72)
                  at android.os.AsyncTask$2.call(AsyncTask.java:333)
                  at java.util.concurrent.FutureTask.run(FutureTask.java:266)
                  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245) 
                  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162) 
                  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) 
                  at java.lang.Thread.run(Thread.java:764) 

这是我的代码：  DatabaseFoody.class

@Database(
     entities = {Ristorante.class},
    version = 2)
public abstract class DatabaseFoody extends RoomDatabase {

private static DatabaseFoody database;

public abstract RistoranteDao getRistoranteDao();

public static DatabaseFoody getIstance(Context context){
    if (database == null){
        database = Room.databaseBuilder(
                context,
                DatabaseFoody.class,
                "db-foody.db").build();
    }

我尝试删除AsyncTask，但问题仍然存在。在doInBackground（）中是正确的插入代码？ RistoranteFragment.class

public class RistoranteFragment extends Fragment {

// TODO: Customize parameter argument names
private static final String ARG_COLUMN_COUNT = "column-count";
// TODO: Customize parameters
private int mColumnCount = 1;
private OnListFragmentInteractionListener mListener;

public RistoranteFragment() {
}

// TODO: Customize parameter initialization
@SuppressWarnings("unused")
public static RistoranteFragment newInstance(int columnCount) {
    RistoranteFragment fragment = new RistoranteFragment();
    Bundle args = new Bundle();
    args.putInt(ARG_COLUMN_COUNT, columnCount);
    fragment.setArguments(args);
    return fragment;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    if (getArguments() != null) {
        mColumnCount = getArguments().getInt(ARG_COLUMN_COUNT);
    }
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_ristorante_list, container, false);

    // Set the adapter
    if (view instanceof RecyclerView) {
        Context context = view.getContext();
        final RecyclerView recyclerView = (RecyclerView) view;
        if (mColumnCount <= 1) {
            recyclerView.setLayoutManager(new LinearLayoutManager(context));
        } else {
            recyclerView.setLayoutManager(new GridLayoutManager(context, mColumnCount));
        }

        new AsyncTask<Void,Void,Void>(){
            @Override
            protected Void doInBackground(Void... voids) {
                recyclerView.setAdapter(new RistoranteRecyclerViewAdapter
                        (DatabaseFoody.getIstance(getContext()).getRistoranteDao().TrovaTutti(),
                                mListener));

                return null;
            }
        }.execute();

    }
    return view;
} 


@Override
public void onDetach() {
    super.onDetach();
    mListener = null;
}

public interface OnListFragmentInteractionListener {
    // TODO: Update argument type and name
    void onListFragmentInteraction(Ristorante item);
}

}

谢谢