Emulator can use database but device not

Question

App can use database to insert items on emulator.But on my device,it can't use database.When it tries gives me an error like

2019-04-06 21:33:17.963 28735-28955/com.timucin.locationholder I/System.out: (HTTPLog)-Static: isSBSettingEnabled false

Here how my database is working

try {
                    MapsActivity.database = openOrCreateDatabase("Places",MODE_PRIVATE,null);
                    Cursor cursor = MapsActivity.database.rawQuery("SELECT * FROM places",null);
                    int nameIx = cursor.getColumnIndex("name");
                    int latitudeIx = cursor.getColumnIndex("latitude");
                    int longitudeIx = cursor.getColumnIndex("longitude");
                    while (cursor.moveToNext()) {
                        nameFromDatabase = cursor.getString(nameIx);
                        String latitudeFromDatabase = cursor.getString(latitudeIx);
                        String longitudeFromDatabase = cursor.getString(longitudeIx);
                        image = cursor.getBlob(3);
                        // names.add(nameFromDatabase);
                        Double l1 = Double.parseDouble(latitudeFromDatabase);
                        Double l2 = Double.parseDouble(longitudeFromDatabase);
                        //   System.out.println("coordinates:"+l1+","+l2);
                        locationFromDatabase = new LatLng(l1, l2);
                        names.add(nameFromDatabase);
                        locations.add(locationFromDatabase);
                        list.add(new Location(nameFromDatabase, image));
                        System.out.println(names);
                    }
                    System.out.println(names);
                    cursor.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
        }

Answer 1

Ok i downloaded you code and run it in AndroidStudio. So a more modern way to avoid doing database operations in the main thread is do it with app executors.

Create a new class in your project that calls AppExecutors and looks like this:

package com.timucin.locationholder;

import android.os.Handler;
import android.os.Looper;
import android.support.annotation.NonNull;

import java.util.concurrent.Executor;
import java.util.concurrent.Executors;

public class AppExecutors {

    // For Singleton instantiation
    private static final Object LOCK = new Object();
    private static AppExecutors sInstance;
    private final Executor diskIO;
    private final Executor mainThread;
    private final Executor networkIO;

    private AppExecutors(Executor diskIO, Executor networkIO, Executor mainThread) {
        this.diskIO = diskIO;
        this.networkIO = networkIO;
        this.mainThread = mainThread;
    }

    public static AppExecutors getInstance() {
        if (sInstance == null) {
            synchronized (LOCK) {
                sInstance = new AppExecutors(Executors.newSingleThreadExecutor(),
                        Executors.newFixedThreadPool(3),
                        new MainThreadExecutor());
            }
        }
        return sInstance;
    }

    public Executor diskIO() {
        return diskIO;
    }

    public Executor mainThread() {
        return mainThread;
    }

    public Executor networkIO() {
        return networkIO;
    }

    private static class MainThreadExecutor implements Executor {
        private Handler mainThreadHandler = new Handler(Looper.getMainLooper());

        @Override
        public void execute(@NonNull Runnable command) {
            mainThreadHandler.post(command);
        }
    }
}

Now you can use this to run the database operations. For example in the MainActivitys onCreate function.

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        final GridView gridView= (GridView) findViewById(R.id.gridView);
        list = new ArrayList<>();

        //Database Operations
        AppExecutors.getInstance().diskIO().execute(new Runnable() {
            @Override
            public void run() {
                try {
                    MapsActivity.database = openOrCreateDatabase("Places",MODE_PRIVATE,null);
                    Cursor cursor = MapsActivity.database.rawQuery("SELECT * FROM places",null);
                    int nameIx = cursor.getColumnIndex("name");
                    int latitudeIx = cursor.getColumnIndex("latitude");
                    int longitudeIx = cursor.getColumnIndex("longitude");
                    while (cursor.moveToNext()) {
                        nameFromDatabase = cursor.getString(nameIx);
                        String latitudeFromDatabase = cursor.getString(latitudeIx);
                        String longitudeFromDatabase = cursor.getString(longitudeIx);
                        image = cursor.getBlob(3);
                        // names.add(nameFromDatabase);
                        Double l1 = Double.parseDouble(latitudeFromDatabase);
                        Double l2 = Double.parseDouble(longitudeFromDatabase);
                        //   System.out.println("coordinates:"+l1+","+l2);
                        locationFromDatabase = new LatLng(l1, l2);
                        names.add(nameFromDatabase);
                        locations.add(locationFromDatabase);
                        list.add(new Location(nameFromDatabase, image));
                        adapter = new LocationListAdapter(getApplicationContext(), R.layout.location_items, list);
                        gridView.setAdapter(adapter);
                        System.out.println(names);
                    }
                    System.out.println(names);
                    cursor.close();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

And its done. You should do so with all your database operations. Actually i could not reproduce the error you get, so i dont know if it will resolve the problem. But anyway, running database operations in the main thread is bad practice and can produce other errors to. Try it ou, i hope it will help.