I have got data from database in variable buffer and I want that data to be displayed in listview

I have got data from database in variable buffer and I want that data to be displayed in ListView

This is my adaper

private void setAdapterData() {

    DBHelper db = new DBHelper(this);

            for (students stud : CustomListViewValuesArr) {
                db.insertContact(stud.getrollno(), stud.getfirst(), stud.getsecond(), stud.getper());


            }

            Log.d("Reading: ", "Reading all contacts..");

            ArrayList<students> stu = db.getAllCotacts();
            res = getResources();

            adapter = new CustomAdapter(CustomListView, stu, res);
            studentlist.setAdapter((ListAdapter) adapter);
        }