Android Sqlitedatabase Nullpointerexception

Okay full code now: DBOpenHelper: public class DBOpenHelper extends SQLiteOpenHelper { private SQLiteDatabase mDatabase; private static final int DATABASE_VERSION = 1; private

Solution 1:

As I see you didn't initialize your database :

privatestaticDBOpenHelperdbHelper=newDBOpenHelper(context);
publicstaticSQLiteDatabasedb= dbHelper.getWritableDatabase();

You need to have a constructor in your DBOpenHelper class where you can set the name of database for your project.You are setting your database in your DB class,but never using it :

privatestaticStringfilename="RTDB.sql";

That's why you are getting NullPointerException, because there is no database which you can get.

EDIT : You can do something like this :

publicDBOpenHelper(Context context, String databaseName) {
    super(context,  databaseName, null, DATABASE_VERSION);
}

in that way when you are initializing your database you can set the name of database that you want to use.

Solution 2:

static Context context;
privatestaticDBOpenHelperdbHelper=newDBOpenHelper(context, "RTDB.sql");

i guess context == null.