initalize

private void initialize() {
        String studentFile = "students.txt";
        String facultyFile = "faculty.txt";

        //LoadStudent loadStudent = new LoadStudent();
        //ArrayList <Person> studentList = loadStudent.loadFromFile(studentFile);

        //LoadFaculty loadFaculty = new LoadFaculty();
        //ArrayList<Person> facultyList = loadFaculty.loadFromFile(facultyFile);

        LoadStudent loadStudent = new LoadStudent(studentFile);
        LoadFaculty loadFaculty = new LoadFaculty(facultyFile);

        Thread t1 = new Thread(loadStudent);
        Thread t2 = new Thread(loadFaculty);

        t1.start();
        t2.start();

        ArrayList <Person> allList = new ArrayList<>();
        while (t1.isAlive() || t2.isAlive()) {
            allList.addAll(loadStudent.getPersonList());
            allList.addAll(loadFaculty.getPersonList());
        }

        this.setPersons(allList);
} // end initialize()