预订应用程序，达到条件时禁用按钮

Question

I want to create a simple reservation application, like when you want to book movie ticket online, except this is a much simplified version.

I have a class names reservation with 8 toggle buttons and 1 button, the user will get to input number of seat they want to book in another class, let's just say 4. In reservation, after the user choose 4 seats, the rest of the toggle button will be disabled to prevent user from choosing more seats. The user will then click the save button, and the data will then be inputted in the Database. Next time when another user open reservation, all of the toggle buttons will be re-enabled except those 4 seats previous user has booked earlier, obviously. Everything is working so far except the part that i bold.

Here's my code :

private static final JToggleButton[] btn = new JToggleButton[8];
private int totalrow, a;
java.sql.Connection connection = null;
Statement statement4 = null;
ResultSet resultSet = null;

private void formWindowActivated(java.awt.event.WindowEvent evt) {  // This is where i load the information that has been saved in the database before.                                   

    try {

        connection = DriverManager.getConnection("jdbc:derby:
        statement4 = (Statement) connection.createStatement();
        resultSet = statement4.executeQuery("SELECT reservationid, seatno, validator FROM reservation WHERE reservationid = '" + time.id + "'");

        String seatno, validator, rsid, id;

        btn[0] = seat1;
        btn[1] = seat2;
        btn[2] = seat3;
        btn[3] = seat4;
        btn[4] = seat5;
        btn[5] = seat6;
        btn[6] = seat7;
        btn[7] = seat8;

        int i = 0;
        while(resultSet.next()){
            seatno = resultSet.getString("seatno");
            validator = resultSet.getString("validator");
            rsid = resultSet.getString("reservationid");

            if(seatno.equals(btn[i].getText()) && validator.equals("reserved")){ //checking if seat i is reserved
                btn[i].setSelected(true);
            }
            else{
                btn[i].setSelected(false);
            }
            i++;
        }

    } catch (SQLException ex) {
         Logger.getLogger(seat.class.getName()).log(Level.SEVERE, null, ex);
    }
}   

public void actionPerformed(ActionEvent e) { // This actionlistener is used to count, if User has choose 4 seats, the code will disable the rest of the button

    try {
        connection = DriverManager.getConnection("jdbc:derby://localhost:1527/Project","root","root");
        statement = (Statement) connection.createStatement();

        btn[0] = seat1;
        btn[1] = seat2;
        btn[2] = seat3;
        btn[3] = seat4;
        btn[4] = seat5;
        btn[5] = seat6;
        btn[6] = seat7;
        btn[7] = seat8;

        a = 0;
        for(JToggleButton btns : btn){
            if (btns.isSelected()){
                a++;
                System.out.println(a);

                if (! btns.isSelected()){
                    System.out.println(a);
                    a--;
                }
            }  
        }

        for(JToggleButton btns : btn){
            if (a >= Integer.parseInt(BookingUI.passenger)){ // This is number of Passenger taken from another class. In this case is 4.
                if(! btns.isSelected()){
                    btns.setEnabled(false);
                }
            }

            else{
                btns.setEnabled(true);
            }
        }

    } catch (SQLException ex) {
        Logger.getLogger(seat.class.getName()).log(Level.SEVERE, null, ex);
    }
}  

Regarding my title, based on my current code and logic, it might not be possible to re-enable the toggle button. So the better way to do it might be to use another logic to disable the toggle button instead.

In the image , seat 1,4,5,8 are chosen by the user. And the rest of the buttons are disabled

Answer 1

Since it's a long implementation, it's difficult to answer with a code solution. There for I will mention my suggestion here.

You have to declare your JToggleButton Array like this btn = new JToggleButton[8]; in a public static context where every class could access it. And when the user reserved a seat you should save the data to DB (or keep in the program memroy, eg : HashMap) on which user reserved the which seat.

After that when you loading the data from the Database you should loop through and get the booked seats which previously inserted and then by accessing that predefined JToggleButton Array and set each booked seat by doing this btns[i].setEnabled(false); (i for the booked index of the seat).
Hope this helps