ارور اجرا نشدن دیتابیس

 این کدها رو از قسمته 4 بحت dataBase آموزشهای استاد آقاجانی نوشتم .. ولی اجرا نمیشه

این قسمتی از ارور هستش

..01-06 04:48:09.401 10131-10131/com.example.lenovo.sample_database E/AndroidRuntime: FATAL EXCEPTION: main
                                                                                    Process: com.example.lenovo.sample_database, PID: 10131
                                                                                    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.lenovo.sample_database/project.activity.SplashActivity}: android.database.sqlite.SQLiteCantOpenDatabaseException: unknown error (code 14): Could not open database

MyDatabaseHelper

package project.Helper;


import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import project.main.G;

public class MyDatabaseHelper extends SQLiteOpenHelper {
    public static final String DB_NAME = "sample.sqlite";
    public static final int DB_VERSION = 2;

    public MyDatabaseHelper(Context context) {
        super(context, G.DB_DIR + "/" + DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        createPersonTable(db);
        createContactTable(db);

    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        if (newVersion == 1) {
            createPersonTable(db);
        }
        if (newVersion == 2) {
            createContactTable(db);
        }

    }

    private void createPersonTable(SQLiteDatabase db) {
        String query = "CREATE  TABLE 'person' (" +
                "'personID' INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL ," +
                " 'firstname' TEXT," +
                " 'lastname' TEXT, " +
                "'gender' INTEGER," +
                " 'email' TEXT UNIQUE ," +
                " 'imageurl' TEXT," +
                " 'creationTime' INTEGER" +
                ")";
        db.execSQL(query);
    }
    private void createContactTable(SQLiteDatabase db) {
        String query = "CREATE  TABLE 'contact' (" +
                "'contactID' INTEGER PRIMARY KEY  AUTOINCREMENT  NOT NULL ," +
                " 'personId' TEXT," +
                " 'lable' TEXT, " +
                " 'phone' TEXT" +
                ")";
        db.execSQL(query);
    }
}

 کلاس G

package project.main;

import android.app.Application;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.util.Log;

import java.io.File;

import project.Helper.MyDatabaseHelper;


public class G extends Application {
    public static G app;
    public static SQLiteDatabase database;
    public static boolean isDataBaseCreate;
    public static final String SDCARD = Environment.getExternalStorageDirectory().getAbsolutePath();
    public static final String BRAND_DIR = SDCARD + "/uncox-learn1";
    public static final String APP_DIR = BRAND_DIR + "/sample_database1";
    public static final String DB_DIR = APP_DIR + "/db1";

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

        app = this;
        Log.i("LOG", "Application On Creat");
    }

    public void createAppDirectories() {
        File db_dir = new File(DB_DIR);
        if (!db_dir.exists()) {
            boolean wasCreated = db_dir.mkdirs();
        }
        createOROpenDatabace();
    }


    public void createOROpenDatabace() {

        if (database != null) {
            return;
        }

        MyDatabaseHelper dbHelper = new MyDatabaseHelper(this);
        database = dbHelper.getWritableDatabase();

        isDataBaseCreate = true;
    }
}

کلاس SplashActivity.java

package project.activity;

import android.Manifest;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;

import com.example.lenovo.sample_database.R;

import project.Helper.RequestHelper;
import project.main.G;

public class SplashActivity extends AppCompatActivity {


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash_activity);

        requestForWriteSDCardPermission();
        OpenMainActivity();
    }

    private void OpenMainActivity() {
        Intent intent = new Intent(this, MainActivity.class);
        this.startActivity(intent);
        this.finish();
    }


    ////----WRITE_EXTERNAL_STORAGE----////


    private void requestForWriteSDCardPermission() {
        RequestHelper request = new RequestHelper(this);
        RequestHelper.OnGrantedListener onGrantedListener = new RequestHelper.OnGrantedListener() {
            @Override
            public void onGranted() {
                G.app.createAppDirectories();
                OpenMainActivity();
            }
        };
        RequestHelper.OnAlreadyGrantedListener onAlreadyGrantedListener = new RequestHelper.OnAlreadyGrantedListener() {
            @Override
            public void onAlreadyGranted() {
                G.app.createOROpenDatabace();
                OpenMainActivity();

            }
        };
        RequestHelper.OnDeniedListener onDeniedListener = new RequestHelper.OnDeniedListener() {
            @Override
            public void onDenied() {
                new AlertDialog.Builder(SplashActivity.this)
                        .setTitle("Permission Requerd")
                        .setMessage("Writing to SDCARD is requred for app")
                        .setPositiveButton("Ask me again", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialogInterface, int i) {
                                requestForWriteSDCardPermission();
                            }
                        })
                        .create()
                        .show();
            }
        };
        request.request(Manifest.permission.WRITE_EXTERNAL_STORAGE, onGrantedListener, onDeniedListener, onAlreadyGrantedListener);
    }

///--- answer ----////

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        RequestHelper.onRequestPermissionResult(requestCode, permissions, grantResults);
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }


}

RequestHelper

package project.Helper;


import android.app.Activity;
import android.content.pm.PackageManager;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;

import java.util.ArrayList;
import java.util.List;

public class RequestHelper {

    private static int lastRecuestCode = 100;
    private static boolean isFirstRequest = true;
    private int requestCode;
    private Activity activity;
    private OnDeniedListener onDeniedListener;
    private OnGrantedListener onGrantedListener;
    private OnAlreadyGrantedListener onAlreadyGrantedListener;
    private String permission;
    private boolean isFinished;
    private static List<RequestHelper> requests = new ArrayList<>();

    public interface OnAlreadyGrantedListener {
        void onAlreadyGranted();
    }

    public interface OnGrantedListener {
        void onGranted();
    }

    public interface OnDeniedListener {
        void onDenied();
    }

    public RequestHelper(Activity activity) {
        this.activity = activity;

    }


    public void request(String permission, OnGrantedListener onGrantedListener, OnDeniedListener onDeniedListener , OnAlreadyGrantedListener onAlreadyGrantedListener) {
        requests.add(this);
        lastRecuestCode++;
        requestCode = lastRecuestCode;
        this.permission = permission;
        this.onDeniedListener = onDeniedListener;
        this.onGrantedListener = onGrantedListener;
        this.onAlreadyGrantedListener = onAlreadyGrantedListener;
        if (isFirstRequest) {
            nextRequest();
            isFirstRequest = false;
        }

    }

    public static void onRequestPermissionResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        for (RequestHelper request : requests) {
            if (requestCode == request.requestCode) {
                if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (request.onGrantedListener != null) {
                        request.onGrantedListener.onGranted();
                    }
                } else {
                    if (request.onDeniedListener != null) {
                        request.onDeniedListener.onDenied();
                    }
                }
                request.isFinished = true;
                nextRequest();
            }
        }
    }

    public static void nextRequest() {
        for (RequestHelper request : requests) {
            if (!request.isFinished) {
                int Granted = ActivityCompat.checkSelfPermission(request.activity, request.permission);
                if (Granted == PackageManager.PERMISSION_DENIED) {
                    ActivityCompat.requestPermissions(request.activity, new String[]{request.permission}, request.requestCode);
                }else{
                    if (request.onAlreadyGrantedListener != null){
                        request.onAlreadyGrantedListener.onAlreadyGranted();
                    }
                }
                return;
            }
            isFirstRequest = true;
        }
    }
}

این کدها رو از قسمته 4بحت dataBase آموزشهای استاد آقاجانی نوشتم .. ولی اجرا نمیشه