NullPointerException:android.content.Context.openOrCreateDatabase 에러

Question

디비에서 삭제 기능 구현중인데

 

삭제 누르면

public void delete(int position) {
    SQLiteDatabase db = getWritableDatabase();
    db.execSQL("DELETE FROM LOGIN WHERE _ID=1;");
    db.close();

}

SQLiteDatabase db = getWritableDatabase();

여기서 에러가 납니다.

java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.sqlite.SQLiteDatabase android.content.Context.openOrCreateDatabase(java.lang.String, int, android.database.sqlite.SQLiteDatabase$CursorFactory)' on a null object reference

 

이 에러가 발생하는데요 어떤걸 해줘야 하나요?

데이터추가 , 셀렉은 잘 동작하고 있습니다.

http://www.masterqna.com/android/69235/%EC%99%B8%EB%B6%80%ED%81%B4%EB%9E%98%EC%8A%A4%EC%97%90%EC%84%9C-sqlite-%EB%94%94%EB%B9%84-%EC%83%9D%EC%84%B1-%EC%97%90%EB%9F%AC%EC%A7%88%EB%AC%B8

위 글답변대로 해봐도 동일한 에러가 납니다.

 

DBHelper 코드입니다.

?

import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteOpenHelper; import android.util.Log; import android.widget.Toast;   import java.util.ArrayList; import java.util.List;   import static android.content.ContentValues.TAG;   public class DBHelper extends SQLiteOpenHelper {     private Context context;     private DBHelper dbHelper;     public DBHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {         super(context, name, factory, version);         this.context = context;     }     @Override public void onCreate(SQLiteDatabase db) {         try {             String DROP_SQL = "drop table if exists LOGIN";             db.execSQL(DROP_SQL);         } catch(Exception ex) {             Log.e(TAG, "Exception in DROP_SQL", ex);         }         StringBuffer sb = new StringBuffer();         sb.append(" CREATE TABLE LOGIN ( ");         sb.append(" _ID INTEGER PRIMARY KEY AUTOINCREMENT, ");         sb.append(" ID TEXT, ");         sb.append(" PW TEXT ) ");         try {             db.execSQL(sb.toString());         } catch(Exception ex) {             Log.e(TAG, "Exception in CREATE_SQL", ex);         }           Toast.makeText(context, R.string.make, Toast.LENGTH_SHORT).show();     }         @Override     public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {         Toast.makeText(context, R.string.upgrade, Toast.LENGTH_SHORT).show();     }         public void addLogin(Login login) {         SQLiteDatabase db = getWritableDatabase();         StringBuffer sb = new StringBuffer();         sb.append(" INSERT INTO LOGIN ( ");         sb.append(" ID, PW ) ");         sb.append(" VALUES ( ?, ? ) ");         if(login.getId().equals("") || login.getPw().equals("")){             Toast.makeText(context, R.string.nodata, Toast.LENGTH_SHORT).show();         }else{             db.execSQL(sb.toString(),                     new Object[]{                             login.getId(),                             login.getPw(),                     });;             Toast.makeText(context, R.string.insert, Toast.LENGTH_SHORT).show();         }     }       public void delete(int position) {         SQLiteDatabase db = getWritableDatabase();         db.execSQL("DELETE FROM LOGIN WHERE _ID=1;");         db.close();       }         public List getAllData() {         StringBuffer sb = new StringBuffer();         sb.append(" SELECT _ID, ID, PW FROM LOGIN ");         SQLiteDatabase db = getReadableDatabase();         Cursor cursor = db.rawQuery(sb.toString(), null);         List list = new ArrayList();         Login login = null;         while (cursor.moveToNext()) {             login = new Login();             login.set_id(cursor.getInt(0));             login.setId(cursor.getString(1));             login.setPw(cursor.getString(2));             list.add(login);         }         return list;       }   }