9.17

package lll;

import java.util.Random;

public class VerificationCodeGenerator {
    public static void main(String[] args) {
        String verificationCode = generateVerificationCode(6);
        System.out.println("验证码：" + verificationCode);
    }

    public static String generateVerificationCode(int length) {
        String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuilder verificationCode = new StringBuilder();
        
        for (int i = 0; i < length; i++) {
            int index = random.nextInt(characters.length());
            verificationCode.append(characters.charAt(index));
        }
        
        return verificationCode.toString();
    }
}

package lll;

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Random;

public class VerificationCodeGeneratorGUI extends JFrame {
    private JTextField lengthTextField;
    private JLabel verificationCodeLabel;

    public VerificationCodeGeneratorGUI() {
        setTitle("验证码生成器");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 200);

        JPanel mainPanel = new JPanel();
        mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.Y_AXIS));
        mainPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

        JPanel lengthPanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        lengthPanel.add(new JLabel("验证码长度:"));
        lengthTextField = new JTextField(10);
        lengthPanel.add(lengthTextField);
        mainPanel.add(lengthPanel);

        JPanel generatePanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        JButton generateButton = new JButton("生成验证码");
        generateButton.addActionListener(new GenerateButtonListener());
        generatePanel.add(generateButton);
        mainPanel.add(generatePanel);

        JPanel verificationCodePanel = new JPanel(new FlowLayout(FlowLayout.LEFT));
        verificationCodePanel.add(new JLabel("验证码:"));
        verificationCodeLabel = new JLabel();
        verificationCodePanel.add(verificationCodeLabel);
        mainPanel.add(verificationCodePanel);

        add(mainPanel);
        setVisible(true);
    }

    private class GenerateButtonListener implements ActionListener {
        @Override
        public void actionPerformed(ActionEvent e) {
            int length = Integer.parseInt(lengthTextField.getText());
            String verificationCode = generateVerificationCode(length);
            verificationCodeLabel.setText(verificationCode);
        }
    }

    public static String generateVerificationCode(int length) {
        String characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random = new Random();
        StringBuilder verificationCode = new StringBuilder();

        for (int i = 0; i < length; i++) {
            int index = random.nextInt(characters.length());
            verificationCode.append(characters.charAt(index));
        }

        return verificationCode.toString();
    }

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

module dada {
	requires java.desktop;
}