javagui如何保存为文本文件

我需要将文本框中的文本保存到文本文件中，但我在其中找到的或生成的任何代码都不起作用，知道吗？像任何人一样？哪种代码可以工作。我必须使用JavaGUI，我的老师在那里教我们java，但没有关于gui的内容，所以我甚至不能保存到文本文件

public class FlightsPanel extends JPanel {
private Flight flightSelected = null;
private JTextField textFieldDepartureAirport;
private JTextField textFieldArrivalAirport;
private JTextField textFieldDepartureDate;
private JTextField textFieldArrivalDate;
private JRadioButton rdbtnBoarding;
private JRadioButton rdbtnChecking;
private JRadioButton rdbtnAvailable;
private JRadioButton rdbtnClosed;
private JTextField textFieldCost;

private DefaultListModel<String> populateFlights() {
    DefaultListModel<String> list = new DefaultListModel<String>();
    ArrayList<Flight> FlightList = MainMenu.getAirlineMgr().getFlightList();

    for (int i = 0; i < FlightList.size(); i++) {
        list.addElement(FlightList.get(i).getFlightNumber());
    }

    return list;
}

private void displayFlight(String number) {
    flightSelected = MainMenu.getAirlineMgr().getFlightByNumber(number);
    textFieldDepartureAirport.setText(flightSelected.getDepartureAirport());
    textFieldArrivalAirport.setText(flightSelected.getArrivalAirport());
    textFieldDepartureDate.setText(flightSelected.getDepartureDate().toString());
    textFieldArrivalDate.setText(flightSelected.getArrivalDate().toString());
    textFieldCost.setText(Double.toString(flightSelected.getCost()));

    if (flightSelected.getFlightStatus() == Flight.Status.AVAILABLE) {
        rdbtnAvailable.setSelected(true);
    } else {
        if (flightSelected.getFlightStatus() == Flight.Status.BOARDING) {
            rdbtnBoarding.setSelected(true);
        } else {
            if (flightSelected.getFlightStatus() == Flight.Status.CHECKING) {
                rdbtnChecking.setSelected(true);
            } else {
                if (flightSelected.getFlightStatus() == Flight.Status.CLOSED) {
                    rdbtnClosed.setSelected(true);
                }
            }
        }
    }
}

private void saveFlight() {
    flightSelected.setDepartureAirport(textFieldDepartureAirport.getText());
    flightSelected.setArrivalAirport(textFieldArrivalAirport.getText());
    flightSelected.setCost(Double.parseDouble(textFieldCost.getText()));

    // flightSelected.setDepartureDate(textFieldDepartureDate.getText());
    // flightSelected.setArrivalDate(textFieldArrivalDate.getText());

    if (rdbtnAvailable.isSelected()) {
        flightSelected.setFlightStatus(Flight.Status.AVAILABLE);
    } else {
        if (rdbtnBoarding.isSelected()) {
            flightSelected.setFlightStatus(Flight.Status.BOARDING);
        } else {
            if (rdbtnChecking.isSelected()) {
                flightSelected.setFlightStatus(Flight.Status.CHECKING);
            } else {
                if (rdbtnClosed.isSelected()) {
                    flightSelected.setFlightStatus(Flight.Status.CLOSED);
                }
            }
        }
    }
}

public FlightsPanel() {
    setBackground(new Color(175, 238, 238));
    setLayout(null);

    JList list = new JList(populateFlights());
    list.addMouseListener(new MouseAdapter() {
        @Override
        public void mouseClicked(MouseEvent arg0) {
            displayFlight(list.getSelectedValue().toString());
        }
    });
    list.setBorder(new LineBorder(new Color(0, 0, 0), 1, true));
    list.setBounds(141, 161, 89, 81);
    add(list);

    JLabel lblNewLabel = new JLabel("Available flights:");
    lblNewLabel.setBounds(141, 136, 121, 14);
    add(lblNewLabel);

    textFieldDepartureAirport = new JTextField();
    textFieldDepartureAirport.setBounds(206, 36, 112, 20);
    add(textFieldDepartureAirport);
    textFieldDepartureAirport.setColumns(10);

    JLabel lblNewLabel_1 = new JLabel("Departure Airport:");
    lblNewLabel_1.setBounds(206, 11, 112, 14);
    add(lblNewLabel_1);

    textFieldArrivalAirport = new JTextField();
    textFieldArrivalAirport.setColumns(10);
    textFieldArrivalAirport.setBounds(10, 36, 112, 20);
    add(textFieldArrivalAirport);

    JLabel lblArrivalAirport = new JLabel("Arrival Airport:");
    lblArrivalAirport.setBounds(10, 11, 112, 14);
    add(lblArrivalAirport);

    textFieldDepartureDate = new JTextField();
    textFieldDepartureDate.setColumns(10);
    textFieldDepartureDate.setBounds(206, 91, 192, 20);
    add(textFieldDepartureDate);

    JLabel lblDepartureDate = new JLabel("Departure Date:");
    lblDepartureDate.setBounds(206, 67, 112, 14);
    add(lblDepartureDate);

    textFieldArrivalDate = new JTextField();
    textFieldArrivalDate.setColumns(10);
    textFieldArrivalDate.setBounds(10, 91, 192, 20);
    add(textFieldArrivalDate);

    JLabel lblArrivalDate = new JLabel("Arrival Date:");
    lblArrivalDate.setBounds(10, 66, 112, 14);
    add(lblArrivalDate);

    rdbtnBoarding = new JRadioButton("BOARDING");
    rdbtnBoarding.setBounds(10, 211, 112, 23);
    add(rdbtnBoarding);

    rdbtnChecking = new JRadioButton("CHECKING");
    rdbtnChecking.setBounds(10, 237, 112, 23);
    add(rdbtnChecking);

    rdbtnAvailable = new JRadioButton("AVAILABLE");
    rdbtnAvailable.setBounds(10, 159, 112, 23);
    add(rdbtnAvailable);

    JLabel lblStatus = new JLabel("Status:");
    lblStatus.setBounds(20, 138, 220, 14);
    add(lblStatus);

    rdbtnClosed = new JRadioButton("CLOSED");
    rdbtnClosed.setBounds(10, 185, 112, 23);
    add(rdbtnClosed);

    ButtonGroup group = new ButtonGroup();
    group.add(rdbtnBoarding);
    group.add(rdbtnChecking);
    group.add(rdbtnAvailable);
    group.add(rdbtnClosed);

    JButton button = new JButton("Cancel");
    button.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            MainMenu.hideFlights();
        }
    });
    button.setBounds(10, 269, 89, 23);
    add(button);

    JButton btnConfirm = new JButton("Confirm");
    btnConfirm.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent arg0) {
            saveFlight();
            MainMenu.hideFlights();

        }
    });
    btnConfirm.setBounds(351, 269, 89, 23);
    add(btnConfirm);

    JLabel lblCost = new JLabel("Cost:");
    lblCost.setBounds(341, 11, 112, 14);
    add(lblCost);

    textFieldCost = new JTextField();
    textFieldCost.setColumns(10);
    textFieldCost.setBounds(328, 36, 112, 20);
    add(textFieldCost);
}

公共类FlightsPanel扩展了JPanel{
私人航班flightSelected=null；
私人JTextField textfield出发机场；
专用JTextField textfield到达端口；
私有JTextField textfield departuredate；
私有JTextField textfield到达日期；
私人JRadioButton rdbtnBoarding；
私人JRadioButton RDBtncheck；
私有JRadioButton rdbtnAvailable；
私有JRadioButton rdbtnClosed；
私有JTextField textfield成本；
private DefaultListModel PopulateFlaghts（）私有{
DefaultListModel列表=新的DefaultListModel（）；
ArrayList FlightList=MainMenu.getAirlineMgr（）.getFlightList（）；
对于（int i=0；iimport java.io.PrintWriter;

try{
    PrintWriter fileWriter = new PrintWriter("myFile.txt", "UTF-8");
    fileWriter.println(textFieldDepartureAirport.selectAll());
    fileWriter.close();
} catch (IOException e) {
   e.printStackTrace();
}