I think it will be very useful to learner. Any student can easily use this code and make his/her project completely.

To get help you can see the video.

Source code for login.

try{
            String sql = "select code from controlCode where code=?";
            pst = con.prepareStatement(sql);
            pst.setString(1, jTextField1.getText());
            rs = pst.executeQuery();
            if(rs.next()){
                dispose();
                new ExamPaper().setVisible(true);
            }else{
                JOptionPane.showMessageDialog(null, "Wrong Information...");
            }
        }catch(Exception e){
            JOptionPane.showMessageDialog(null, e);
        }

Interface of after run the Login page.