java登录界面增删改减

好的，我可以为您提供一个可以增删改查用户的Java登录界面代码，您可以根据您的需求进行修改和优化。

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;

public class LoginGUI extends JFrame implements ActionListener {
    private JLabel userLabel, passwordLabel;
    private JTextField userField;
    private JPasswordField passwordField;
    private JButton loginButton, resetButton, addUserButton, deleteUserButton, updateUserButton;
    private JTextArea userArea;
    private ArrayList<User> userList;

    public LoginGUI() {
        setTitle("登录界面");
        setSize(600, 400);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLocationRelativeTo(null);

        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints constraints = new GridBagConstraints();
        constraints.insets = new Insets(10, 10, 10, 10);

        userLabel = new JLabel("用户名: ");
        constraints.gridx = 0;
        constraints.gridy = 0;
        panel.add(userLabel, constraints);

        userField = new JTextField(20);
        constraints.gridx = 1;
        constraints.gridy = 0;
        panel.add(userField, constraints);

        passwordLabel = new JLabel("密码: ");
        constraints.gridx = 0;
        constraints.gridy = 1;
        panel.add(passwordLabel, constraints);

        passwordField = new JPasswordField(20);
        constraints.gridx = 1;
        constraints.gridy = 1;
        panel.add(passwordField, constraints);

        loginButton = new JButton("登录");
        loginButton.addActionListener(this);
        constraints.gridx = 0;
        constraints.gridy = 2;
        panel.add(loginButton, constraints);

        resetButton = new JButton("重置");
        resetButton.addActionListener(this);
        constraints.gridx = 1;
        constraints.gridy = 2;
        panel.add(resetButton, constraints);

        addUserButton = new JButton("添加用户");
        addUserButton.addActionListener(this);
        constraints.gridx = 2;
        constraints.gridy = 0;
        panel.add(addUserButton, constraints);

        deleteUserButton = new JButton("删除用户");
        deleteUserButton.addActionListener(this);
        constraints.gridx = 2;
        constraints.gridy = 1;
        panel.add(deleteUserButton, constraints);

        updateUserButton = new JButton("修改用户");
        updateUserButton.addActionListener(this);
        constraints.gridx = 2;
        constraints.gridy = 2;
        panel.add(updateUserButton, constraints);

        userArea = new JTextArea(10, 30);
        userArea.setEditable(false);
        JScrollPane scrollPane = new JScrollPane(userArea);
        constraints.gridx = 3;
        constraints.gridy = 0;
        constraints.gridheight = 3;
        panel.add(scrollPane, constraints);

        add(panel);
        setVisible(true);

        userList = new ArrayList<User>();
        userList.add(new User("admin", "admin", "管理员"));
        userList.add(new User("user", "user", "普通用户"));
        updateUserArea();
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == loginButton) {
            String user = userField.getText();
            String password = new String(passwordField.getPassword());
            User loginUser = null;

            for (User u : userList) {
                if (u.getUsername().equals(user) && u.getPassword().equals(password)) {
                    loginUser = u;
                    break;
                }
            }

            if (loginUser != null) {
                JOptionPane.showMessageDialog(this, "欢迎您！" + loginUser.getRole() + " " + loginUser.getUsername() + " 登录成功！");
            } else {
                JOptionPane.showMessageDialog(this, "用户名或密码错误！");
            }
        } else if (e.getSource() == resetButton) {
            userField.setText("");
            passwordField.setText("");
        } else if (e.getSource() == addUserButton) {
            String username = JOptionPane.showInputDialog(this, "请输入用户名：");
            String password = JOptionPane.showInputDialog(this, "请输入密码：");
            String role = JOptionPane.showInputDialog(this, "请输入角色：");
            userList.add(new User(username, password, role));
            updateUserArea();
        } else if (e.getSource() == deleteUserButton) {
            String username = JOptionPane.showInputDialog(this, "请输入要删除的用户名：");
            for (User u : userList) {
                if (u.getUsername().equals(username)) {
                    userList.remove(u);
                    break;
                }
            }
            updateUserArea();
        } else if (e.getSource() == updateUserButton) {
            String username = JOptionPane.showInputDialog(this, "请输入要修改的用户名：");
            for (User u : userList) {
                if (u.getUsername().equals(username)) {
                    String newPassword = JOptionPane.showInputDialog(this, "请输入新密码：");
                    String newRole = JOptionPane.showInputDialog(this, "请输入新角色：");
                    u.setPassword(newPassword);
                    u.setRole(newRole);
                    break;
                }
            }
            updateUserArea();
        }
    }

    public void updateUserArea() {
        userArea.setText("");
        for (User u : userList) {
            userArea.append(u.getUsername() + " " + u.getPassword() + " " + u.getRole() + "\n");
        }
    }

    public static void main(String[] args) {
        new LoginGUI();
    }
}

class User {
    private String username;
    private String password;
    private String role;

    public User(String username, String password, String role) {
        this.username = username;
        this.password = password;
        this.role = role;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    public String getRole() {
        return role;
    }

    public void setRole(String role) {
        this.role = role;
    }
}

这个登录界面除了原来的用户名输入框、密码输入框、登录按钮和重置按钮外，还增加了添加用户按钮、删除用户按钮、修改用户按钮和用户信息显示区域。当用户点击添加用户按钮时，程序会弹出对话框让用户输入新用户的信息，然后将新用户添加到用户列表中并更新用户信息显示区域。当用户点击删除用户按钮时，程序会弹出对话框让用户输入要删除的用户名，然后在用户列表中查找该用户并将其删除，最后更新用户信息显示区域。当用户点击修改用户按钮时，程序会弹出对话框让用户输入要修改的用户名，然后在用户列表中查找该用户并将其密码和角色修改为新值，最后更新用户信息显示区域。

上面的代码使用了一个User类来表示用户，包括用户名、密码和角色三个属性，同时提供了对这些属性的访问和修改方法。用户列表使用了一个ArrayList<User>对象来存储，每次添加、删除或修改用户时都需要更新用户信息显示区域。希望能对您有所帮助！