java - Jdialog 将用户凭据传回其包含的 JFrame？或者，JFrame 从其 JDialog 获取凭据？

Question

如何将用户凭据传回到包含的 JFrame，以便 JFrame 知道特定用户？ JFrame 有一个 main 方法。

包含的 JFrame 能否以某种方式从 Dialog 中获取用户？

当jbtOk actionListener找到可接受的User时，然后...？

package legacy.gui.general;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.Arrays;
import java.util.List;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingConstants;
import legacy.database.User;
import legacy.database.Users;

public class LoginDialog extends javax.swing.JDialog {

    private static final Logger log = Logger.getLogger(LoginDialog.class.getName());
    private final JLabel jlblUsername = new JLabel("Username");
    private final JLabel jlblPassword = new JLabel("Password");
    private final JTextField jtfUsername = new JTextField(15);
    private final JPasswordField jpfPassword = new JPasswordField();
    private final JButton jbtOk = new JButton("Login");
    private final JButton jbtCancel = new JButton("Cancel");
    private final JLabel jlblStatus = new JLabel(" ");

    public LoginDialog() {
        this(null, true);
    }

    public LoginDialog(java.awt.Frame parent, boolean modal) {
        super(parent, modal);
        log.info("simple constructor..");
        initComponents();
    }

    public LoginDialog(final JFrame parent, boolean modal) {
        super(parent, modal);
        log.info("complex constructor..");
        JPanel p3 = new JPanel(new GridLayout(2, 1));
        p3.add(jlblUsername);
        p3.add(jlblPassword);
        JPanel p4 = new JPanel(new GridLayout(2, 1));
        p4.add(jtfUsername);
        p4.add(jpfPassword);
        JPanel p1 = new JPanel();
        p1.add(p3);
        p1.add(p4);
        JPanel p2 = new JPanel();
        p2.add(jbtOk);
        p2.add(jbtCancel);
        JPanel p5 = new JPanel(new BorderLayout());
        p5.add(p2, BorderLayout.CENTER);
        p5.add(jlblStatus, BorderLayout.NORTH);
        jlblStatus.setForeground(Color.RED);
        jlblStatus.setHorizontalAlignment(SwingConstants.CENTER);
        setLayout(new BorderLayout());
        add(p1, BorderLayout.CENTER);
        add(p5, BorderLayout.SOUTH);
        pack();
        setLocationRelativeTo(null);
        setDefaultCloseOperation(DISPOSE_ON_CLOSE);
        addWindowListener(new WindowAdapter() {
            @Override
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        jbtOk.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                List<User> users = new Users().getUsers();
                for (User u : users) {
                    if (Arrays.equals(u.getPassword().toCharArray(), jpfPassword.getPassword())
                            && u.getUser().equals(jtfUsername.getText())) {
                        parent.setVisible(true);
                        setVisible(false);
                    } else {
                        jlblStatus.setText("Invalid username or password");
                    }
                }
            }
        });
        jbtCancel.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                setVisible(false);
                parent.dispose();
                System.exit(0);
            }
        });
    }

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 580, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 389, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>                        

    // Variables declaration - do not modify                     
    // End of variables declaration                   
}

JFrame 创建对话框:

public MainFrame() {
    initComponents();
    passDialog = new LoginDialog(this, true);
    passDialog.setVisible(true);
    //     setExtendedState(JFrame.MAXIMIZED_BOTH);
}

Answer 1

首先，创建一个名为User的私有(private)实例字段...

private User user;

接下来，更改您的Login ActionListener来存储匹配的用户...

jbtOk.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        List<User> users = new Users().getUsers();
        for (User u : users) {
            if (Arrays.equals(u.getPassword().toCharArray(), jpfPassword.getPassword())
                    && u.getUser().equals(jtfUsername.getText())) {
                user = u;
                dispose();
                break;
            } else {
                jlblStatus.setText("Invalid username or password");
            }
        }
    }
});

接下来，在 LoginDialog 中创建一个方法，以允许调用者获取 User 值...

public User getUser() {
    return user;
}

接下来，当LoginDialog关闭时，获取User...

public MainFrame() {
    initComponents();
    passDialog = new LoginDialog(this, true);
    passDialog.setVisible(true);
    User user = passDialog.getUser();
}

旁注

• 不要尝试通过 LoginDialog 控制调用者。例如，如果用户选择“取消”，则登录对话框不负责确定应该发生什么情况。 LoginDialog 应该简单地完成它的契约(Contract)工作(收集用户详细信息并验证凭据)，并将其余的工作留给调用者...