Any alternative to this code?

I have tried many things to make this code work, it consists of showing an AlertDialog/description when taping on an element/marker from map. The problem is that 3 of 4 markers work (but not showing the right description. it looks like the previous one) and the last force closes the app with the logcat error:

CursorIndexOutOfBoundsException: Index 4 requested, with a size of 4

Code:

@Override
        protected boolean onTap(int index) {
            db = openHelper.getWritableDatabase();

            String[] columns_descri = new String[] {COL_DESCR开发者_高级运维I};

            Cursor cur = db.query(true, TABLE_COORD, columns_descri,null, null, null, null, null, null);

            cur.moveToPosition(index);
                String description = cur.getString(cur.getColumnIndexOrThrow(COL_DESCRI));

                AlertDialog.Builder dialog = new AlertDialog.Builder(Geo.this);
                dialog.setTitle("Infos.");
                dialog.setMessage(description);
                dialog.setPositiveButton("OK", new OnClickListener() {    
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
                dialog.show();

             cur.close();
             db.close();

            return true;
        }

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you should not use directly index, instead, you probably have an adapter somewhere that can give you either the object you want to display or the _id of your row, which you can use to forge a precise request

edit

You are using a ItemizedOverlay. Therefore, you can get the tapped item by :

public void onTap(int index) {
    Item item = getItem(index);
}

Then I suppose you can get the relevant informations from the item rather than from a cursor.

---

Just use cur.moveToPosition(index - 1);