java - JList 未在单独的 Pane 上更新(Swing、Java)

Question

在我的第一个名为“密码保管库”的选项卡上，我有一个 JList，其中包含存储密码的“网站”列表。在第二个选项卡上，我有一个添加“密码”功能。当我添加密码时，JList 仅在 Pane 上更新。当我切换回另一个选项卡“密码保管库”时，它尚未更新。当我重新启动该程序时，它已更新。我使用了一个字段，所以这不是局部变量的问题。

public final class PasswordManagerView1 extends JFrame
    implements PasswordManagerView, ListSelectionListener {
/**
 * JList.
 */
private JList<String> list;

/**
 * JButtons.
 */
private JButton enter, unlock, reset, buttonAddEnter;

/**
 * Controller.
 */
private PasswordManagerController controller;

/**
 * Dimensions.
 */
private Dimension maxSize;

/**
 * JTabbedPanes.
 */
private JTabbedPane tabbedPane;

/**
 * JTextField.
 */
private JTextField passwordDisplay, textField;

/**
 * PasswordField.
 */
private JPasswordField passwordField, resetField, passwordFieldadd;

/**
 * Useful Constants.
 */
private static final int MAX_SIZE_HORI = 800, MAX_SIZE_VERTI = 400,
        EMPTY_BORDER_SIZE = 5;

/**
 * Constructor.
 */
public PasswordManagerView1() {
    super("Password Manager");
    JTabbedPane tabbedPane = new JTabbedPane();
    //Initial JPanel creation
    tabbedPane.setBorder(
            new EmptyBorder(PasswordManagerView1.EMPTY_BORDER_SIZE,
                    PasswordManagerView1.EMPTY_BORDER_SIZE,
                    PasswordManagerView1.EMPTY_BORDER_SIZE,
                    PasswordManagerView1.EMPTY_BORDER_SIZE));
    this.maxSize = new Dimension(PasswordManagerView1.MAX_SIZE_HORI,
            PasswordManagerView1.MAX_SIZE_VERTI);
    tabbedPane.setPreferredSize(this.maxSize);
    this.getContentPane().add(tabbedPane);

    //Initial JTabbedPane creation

    //Tab creation
    JComponent panel1 = this.makePasswordVault();
    ImageIcon icon = new ImageIcon("lock-icon.png");
    tabbedPane.addTab("Password Vault", icon, panel1,
            "View the passwords in the vault");
    JComponent panel3 = this.makeAddPanel("Add Password");
    tabbedPane.addTab("Add Password", icon, panel3,
            "Add passwords to the vault");
    //JComponent panel2 = this.makeAddPanel("ALSO ADDS");
    //tabbedPane.addTab("Delete Password", icon, panel2,
    //        "Deletes a password from the vault");

    JComponent panel4 = this.makeInfoPanel();
    tabbedPane.addTab("Info", icon, panel4,
            "View settings and program info");
    //Pack up
    this.setResizable(false);
    this.pack();
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.setVisible(true);
}

@Override
public JComponent makeAddPanel(String text) {
    JPanel panel = new JPanel();
    panel.setLayout(null);
    //Creation of string array of with stores
    String[] listContentC = this.getStore();

    this.list = new JList<>(listContentC);
    this.list.setBounds(0, 0, 233, 360);
    JScrollPane pane = new JScrollPane(this.list);
    pane.setBounds(0, 0, 233, 360);
    panel.add(pane);
    JLabel labelAdd = new JLabel("Add Password");
    labelAdd.setHorizontalAlignment(SwingConstants.CENTER);
    labelAdd.setFont(new Font("Times New Roman", Font.PLAIN, 24));
    labelAdd.setBounds(427, 38, 163, 31);
    panel.add(labelAdd);

    this.passwordFieldadd = new JPasswordField();
    this.passwordFieldadd.setBounds(536, 100, 116, 22);
    panel.add(this.passwordFieldadd);

    this.textField = new JTextField();
    this.textField.setBounds(375, 100, 116, 22);
    panel.add(this.textField);

    JLabel lblWebsite = new JLabel("Website");
    lblWebsite.setHorizontalAlignment(SwingConstants.CENTER);
    lblWebsite.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    lblWebsite.setBounds(401, 126, 56, 16);
    panel.add(lblWebsite);

    JLabel lblPassword = new JLabel("Password");
    lblPassword.setHorizontalAlignment(SwingConstants.CENTER);
    lblPassword.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    lblPassword.setBounds(566, 126, 56, 16);
    panel.add(lblPassword);

    this.buttonAddEnter = new JButton("Enter");
    this.buttonAddEnter.setBounds(465, 161, 97, 25);
    panel.add(this.buttonAddEnter);
    this.buttonAddEnter.addActionListener(this);
    return panel;
}

@Override
public JComponent makeInfoPanel() {
    JPanel panel = new JPanel();
    panel.setLayout(new GridLayout(1, 1));
    StringBuilder toPrint = new StringBuilder();
    SimpleReader in = new SimpleReader1L("data/Notice.txt");
    while (!in.atEOS()) {
        toPrint.append(in.nextLine() + "\n");
    }
    String toPrintString = toPrint.toString();
    JTextArea noticeText = new JTextArea(toPrintString);
    noticeText.setEditable(false);
    JScrollPane noticeTextScroll = new JScrollPane(noticeText);
    panel.add(noticeTextScroll);
    in.close();
    return panel;

}

@Override
public JComponent makePasswordVault() {
    JPanel panel = new JPanel();
    panel.setLayout(null);
    /*
     * Ask for help on this.
     *
     * I would have liked to create the listContentC by passing nothing into
     * the controller and then the controller using the model to extract the
     * data from a text file. However, my array was always initialized to
     * something null and caused a runtime error.
     *
     *
     */

    //Creation of string array of with stores
    String[] listContentC = this.getStore();

    //GUI setup of list
    this.list = new JList<>(listContentC);
    this.list.setLayoutOrientation(JList.VERTICAL);
    this.list.addListSelectionListener(this);
    JScrollPane pane = new JScrollPane(this.list);
    pane.setBounds(0, 0, 233, 360);
    panel.add(pane);

    //The label creation (for instructions)
    JLabel labelA = new JLabel("the store and press enter!");
    labelA.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    labelA.setBounds(294, 70, 157, 31);
    panel.add(labelA);
    JLabel labelB = new JLabel("To view a password, click on");
    labelB.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    labelB.setBounds(284, 54, 163, 31);
    panel.add(labelB);

    //Enter button creation
    this.enter = new JButton("Enter");
    this.enter.setBounds(303, 128, 116, 25);
    panel.add(this.enter);
    this.enter.setEnabled(false);
    this.enter.addActionListener(this);

    //Password Display field creation
    this.passwordDisplay = new JTextField();
    this.passwordDisplay.setBackground(Color.WHITE);
    this.passwordDisplay.setEditable(false);
    this.passwordDisplay
            .setFont(new Font("Times New Roman", Font.PLAIN, 13));
    this.passwordDisplay.setHorizontalAlignment(SwingConstants.CENTER);
    this.passwordDisplay.setText("");
    this.passwordDisplay.setBounds(303, 247, 116, 22);
    panel.add(this.passwordDisplay);
    this.passwordDisplay.setColumns(10);

    //Password Label creation
    JLabel passwordLabel = new JLabel("Password:");
    passwordLabel.setHorizontalAlignment(SwingConstants.CENTER);
    passwordLabel.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    passwordLabel.setBounds(336, 218, 56, 16);
    panel.add(passwordLabel);

    //Master password notice
    JLabel mastPass = new JLabel("Enter master password to unlock vault:");
    mastPass.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    mastPass.setBounds(532, 54, 218, 31);
    panel.add(mastPass);

    //Password Field
    this.passwordField = new JPasswordField();
    this.passwordField.setBounds(532, 128, 116, 24);
    panel.add(this.passwordField);

    //Unlock button
    this.unlock = new JButton("Unlock");
    this.unlock.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    this.unlock.setBounds(660, 127, 97, 25);
    panel.add(this.unlock);
    this.unlock.addActionListener(this);

    //New setup label
    JLabel labelC = new JLabel("Reset/Set up new master pass:");
    labelC.setHorizontalAlignment(SwingConstants.CENTER);
    labelC.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    labelC.setBounds(532, 217, 218, 16);
    panel.add(labelC);

    //New setup label
    JLabel defaultLabel = new JLabel("Default Password = \"password\"");
    defaultLabel.setHorizontalAlignment(SwingConstants.CENTER);
    defaultLabel.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    defaultLabel.setBounds(560, 77, 171, 16);
    panel.add(defaultLabel);

    this.resetField = new JPasswordField();
    this.resetField.setBounds(532, 246, 116, 24);
    panel.add(this.resetField);

    this.reset = new JButton("Update");
    this.reset.setFont(new Font("Times New Roman", Font.PLAIN, 13));
    this.reset.setBounds(660, 245, 97, 25);
    this.reset.setEnabled(false);
    panel.add(this.reset);
    this.reset.addActionListener(this);
    return panel;
}

@Override
public String[] getStore() {

    int storeCount = 0;
    SimpleReader in = new SimpleReader1L("data/store.txt");
    while (!in.atEOS()) {
        storeCount++;
        in.nextLine();
    }
    in.close();
    String[] listContentC = new String[storeCount];
    SimpleReader in2 = new SimpleReader1L("data/store.txt");
    for (int i = 0; i < storeCount; i++) {
        listContentC[i] = in2.nextLine();
    }
    in2.close();
    return listContentC;
}

@Override
public void registerObserver(PasswordManagerController controller) {
    this.controller = controller;
}

@Override
public void updateEnterButtonVaultTab(boolean result) {
    this.enter.setEnabled(result);
}

@Override
public void actionPerformed(ActionEvent event) {
    //Wait cursor
    this.setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));

    //What button was pressed
    Object source = event.getSource();
    if (source == this.enter) {
        int index = this.list.getSelectedIndex();
        System.out.println(index);
        if (this.list.getSelectedIndex() != -1) {
            this.controller.processEnterEvent(this.list.getSelectedValue());
        }
    } else if (source == this.unlock) {
        this.controller
                .processUnlockEvent(this.passwordField.getPassword());
    } else if (source == this.reset) {
        this.controller.processResetEvent(this.resetField.getPassword());
    } else if (source == this.buttonAddEnter) {
        this.controller.processAddEvent(this.textField.getText(),
                this.passwordFieldadd.getPassword());
        //needs done in model
        this.updateListModel();
    }
    this.setCursor(Cursor.getDefaultCursor());
}

@Override
public void updateListModel() {
    //MOVE TO THE MODEL
    String[] temp = this.getStore();
    DefaultListModel<String> temp2 = new DefaultListModel<>();
    for (int i = 0; i < temp.length; i++) {
        temp2.addElement(temp[i]);
    }
    this.list.setModel(temp2);
}

@Override
public JTabbedPane getTabbedPane() {
    return this.tabbedPane;
}

@Override
public void setTabbedPane(JTabbedPane tabbedPane) {
    this.tabbedPane = tabbedPane;
}

@Override
public void updatePasswordField() {
    this.passwordField.setText("");
}

@Override
public void updateResetPasswordDisplay() {
    this.resetField.setText("");
}

@Override
public void displayWrongPass() {
    JOptionPane.showMessageDialog(this, "Wrong password entered!");

}

@Override
public void displayUpdatedPass() {
    JOptionPane.showMessageDialog(this, "Master password updated!");
}

@Override
public void updateResetButton(boolean result) {
    this.reset.setEnabled(result);
}

@Override
public void updatePasswordDisplay(char[] password) {
    StringBuilder passwordCreation = new StringBuilder();
    for (int i = 0; i < password.length; i++) {
        passwordCreation.append(password[i]);
    }
    this.passwordDisplay.setText(passwordCreation.toString());

}

@Override
public JComponent makeTextPanel(String text) {
    // TODO Auto-generated method stub
    return null;
}

@Override
public void valueChanged(ListSelectionEvent arg0) {

}

}

Answer 1

您的构造函数调用 makePasswordPanel()，其中包含以下行:

   this.list = new JList<>(listContentC);

构造函数然后调用 makeAddPanel()，其中包含以下行:

   this.list = new JList<>(listContentC);

现在您已经丢弃了第一个列表的句柄，并将其替换为对新列表的引用。然后在 updateListModel 中，更改 this.list (即 makeAddPanel 列表)的模型。无法同时更新密码面板的模型，因为您已放弃对该面板的引用。