データベースエラー：ヌルオブジェクト参照上の仮想メソッドを呼び出そうと「カーソル.getScene（）」

Question

java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.Cursor com.example.munna.homeauto.DatabaseCreation.getScene()' on a null object reference

public class Server extends Activity { 

    DatabaseCreation myDb; 
    int i; 

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

     myDb = new DatabaseCreation(this); 

    } 

    public void server_check() { 
     System.out.println("client"); 
     int j; 
     int k; 
     Cursor scene = myDb.getScene();//unfortunetly stops when cursor comes to this step 
     while (scene.moveToNext()) { 
      System.out.println("client 1"); 
      for (i = 0; i <= 5; i++) { 
       scene.getString(i); 
       System.out.println("client 2"); 
       // my code for server message 
      } 

     } 

    } 
} 

Answer 1

if (sence.hasNext()) { 
while (scene.moveToNext()) { 
    System.out.println("client 1"); 
    for (i = 0; i <= 5; i++) { 
     System.out.println(scene.getString(i)); 
     } 
    } 
} 

グッドラック:)