public Secretarapp() throws FileNotFoundException, IOException {
        initComponents();
        BufferedReader fisier = new BufferedReader(new FileReader("clase"));
            ArrayList<String> vector = new ArrayList<>();
            for(String line; (line = fisier.readLine())!= null;){
                vector.add(line);                  
            }
            for(int i=0;i<vector.size();i++)
                clasaDeSters.addItem(vector.get(i));
        
    }