Android, cannot re-open already closed connection for query

I am trying to read data from an SQLite database so that a CursorAdapter can format it into my list view items, but I am receiving an error when I try to use a rawQuery saying that I am attempting to re-open an already closed object. I've looked into this and this error mostly occurs when people try to use their cursor objects after having closed the cursor, but my cursor close is at the end of the method and a new one is created on each call, and the db.close() method has been removed, but to no avail. I've included the relevant classes.

MainActivityFragment

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    //Primary View Inflator
    final View rootView = inflater.inflate(R.layout.fragment_main, container, false);

    //Databse instatiation
    final MySQLiteHelper mDbHelper = new MySQLiteHelper(getActivity());

button2.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {

        if((noteTitle.getText().toString().trim()).equals("")){
            Toast.makeText(getActivity().getBaseContext(), "No Title Specified", Toast.LENGTH_SHORT).show();
        }else {
            String noteTitleString = noteTitle.getText().toString();
            String noteBodyString = noteBody.getText().toString();

            Toast.makeText(getActivity().getBaseContext(), "Added: " + noteTitleString, Toast.LENGTH_SHORT).show();

            //Clear text fields and hide keyboard
            noteTitle.getText().clear();
            noteBody.getText().clear();
            final InputMethodManager imm = (InputMethodManager)
                    getActivity().getSystemService(Context.INPUT_METHOD_SERVICE);
            imm.hideSoftInputFromWindow(getView().getWindowToken(), 0);

            //Write new row into database and refresh listview
            addNotes(mDbHelper, noteTitleString, noteBodyString);
            readNotes(rootView);
        }
        }
    });
}

private void addNotes(MySQLiteHelper mDbHelper, String title, String body){

    // Gets the data repository in write mode
    SQLiteDatabase db = mDbHelper.getWritableDatabase();

// Create a new map of values, where column names are the keys
    ContentValues values = new ContentValues();
    values.put(FeedEntry.COLUMN_NAME_TITLE, title);
    values.put(FeedEntry.COLUMN_NAME_BODY, body);

// Insert the new row, returning the primary key value of the new row
    db.insert(
            FeedEntry.TABLE_NAME,
            null,
            values);

//        db.close();
}

private void readNotes(View rootView){

    MySQLiteHelper mDbHelper = new MySQLiteHelper(getActivity());
    SQLiteDatabase db = mDbHelper.getWritableDatabase(); //changed from readable

    // Query for items from the database and get a cursor back
    Cursor notesCursor = db.rawQuery("SELECT  * FROM notes", null);

    // Find ListView to populate
    ListView notelv = (ListView) rootView.findViewById(R.id.note_list_view);
    // Setup cursor adapter using cursor from last step
    final NotesListAdapter noteAdapter = new NotesListAdapter(rootView.getContext(), notesCursor, 0);
    //// Attach cursor adapter to the ListView
    notelv.setAdapter(noteAdapter);

    notesCursor.close();

}

MySQLiteHelper

public class MySQLiteHelper extends SQLiteOpenHelper {

private static final String TEXT_TYPE = " TEXT";
private static final String INT_TYPE = " INTEGER";
private static final String COMMA_SEP = ",";
private static final String SQL_CREATE_ENTRIES =
        "CREATE TABLE " + FeedEntry.TABLE_NAME + " (" +
                FeedEntry._ID + " INTEGER PRIMARY KEY," +
                FeedEntry.COLUMN_NAME_TITLE + TEXT_TYPE + COMMA_SEP +
                FeedEntry.COLUMN_NAME_BODY + TEXT_TYPE +
        " )";

private static final String SQL_DELETE_ENTRIES =
        "DROP TABLE IF EXISTS " + FeedEntry.TABLE_NAME;



// If you change the database schema, you must increment the database version.
public static final int DATABASE_VERSION = 1;
public static final String DATABASE_NAME = "FeedReader.db";

public MySQLiteHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
public void onCreate(SQLiteDatabase db) {
    db.execSQL(SQL_CREATE_ENTRIES);
}
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // This database is only a cache for online data, so its upgrade policy is
    // to simply to discard the data and start over
    db.execSQL(SQL_DELETE_ENTRIES);
    onCreate(db);
}
public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    onUpgrade(db, oldVersion, newVersion);
}
}

Error Stack

Process: com.example.ggould.scribble, PID: 8408
java.lang.IllegalStateException: attempt to re-open an already-closed object: SQLiteQuery: SELECT  * FROM notes
        at android.database.sqlite.SQLiteClosable.acquireReference(SQLiteClosable.java:55)
        at android.database.sqlite.SQLiteQuery.fillWindow(SQLiteQuery.java:58)
        at android.database.sqlite.SQLiteCursor.fillWindow(SQLiteCursor.java:152)
        at android.database.sqlite.SQLiteCursor.onMove(SQLiteCursor.java:124)
        at android.database.AbstractCursor.moveToPosition(AbstractCursor.java:214)
        at android.widget.CursorAdapter.getView(CursorAdapter.java:245)
        at android.widget.AbsListView.obtainView(AbsListView.java:2344)
        at android.widget.ListView.measureHeightOfChildren(ListView.java:1270)
        at android.widget.ListView.onMeasure(ListView.java:1182)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at android.support.v7.internal.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:124)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.support.v7.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:393)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:722)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:613)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5463)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:430)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2560)
        at android.view.View.measure(View.java:17430)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2001)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1166)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1372)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1054)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5779)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767)
        at android.view.Choreographer.doCallbacks(Choreographer.java:580)
        at android.view.Choreographer.doFrame(Choreographer.java:550)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753)
        at android.os.Handler.handleCallback(Handler.java:739)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:135)
        at android.app.ActivityThread.main(ActivityThread.java:5221)
        at java.lang.reflect.Method.invoke(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:372)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)