口算题卡

import javax.swing.;
import java.awt.;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Random;

class Main extends JFrame {
private JTextArea questionArea;
private JTextField[] answerFields;
private JButton submitButton;
private JLabel resultLabel;
private int correctCount = 0;
private int wrongCount = 0;
private Random random = new Random();
private int remainingTime = 300; // 以秒为单位的剩余时间，修改为5分钟
private ArrayList questionList = new ArrayList<>();
private Date startTime;

public Main() {
    setTitle("数学小测验");
    setSize(600, 400);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel panel = new JPanel();
    panel.setLayout(new BorderLayout());

    questionArea = new JTextArea();
    generateAllQuestions();
    JScrollPane scrollPane = new JScrollPane(questionArea);
    panel.add(scrollPane, BorderLayout.CENTER);

    JPanel answerPanel = new JPanel();
    answerPanel.setLayout(new GridLayout(30, 2));
    answerFields = new JTextField[30];
    for (int i = 0; i < 30; i++) {
        answerFields[i] = new JTextField();
        answerPanel.add(new JLabel("第" + (i + 1) + "题答案："));
        answerPanel.add(answerFields[i]);
    }
    panel.add(answerPanel, BorderLayout.SOUTH);

    submitButton = new JButton("提交答案");
    submitButton.addActionListener(new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            checkAnswers();
            Date endTime = new Date();
            long diff = endTime.getTime() - startTime.getTime();
            long diffSeconds = diff / 1000;
            long minutes = diffSeconds / 60;
            long seconds = diffSeconds % 60;
            JOptionPane.showMessageDialog(null, "你完成所有题目共用了 " + minutes + " 分钟 " + seconds + " 秒");
            showFullResults();
        }
    });

    resultLabel = new JLabel();
    panel.add(submitButton, BorderLayout.EAST);
    panel.add(resultLabel, BorderLayout.NORTH);

    add(panel);

    startTime = new Date();
}

private void generateAllQuestions() {
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < 30; i++) {
        int n1 = random.nextInt(100);
        int n2 = random.nextInt(100);
        int choose = random.nextInt(4);
        String op;
        int expectedResult;
        switch (choose) {
            case 0:
                op = "+";
                expectedResult = n1 + n2;
                break;
            case 1:
                if (n1 < n2) {
                    int temp = n1;
                    n1 = n2;
                    n2 = temp;
                }
                op = "-";
                expectedResult = n1 - n2;
                break;
            case 2:
                // 确保乘法结果不超过三位数
                do {
                    n1 = random.nextInt(100);
                    n2 = random.nextInt(100);
                } while (n1 * n2 >= 1000);
                op = "*";
                expectedResult = n1 * n2;
                break;
            case 3:
                n2 = getDivisor(n1, random);
                op = "/";
                expectedResult = n1 / n2;
                break;
            default:
                op = "%";
                expectedResult = n1 % n2;
                break;
        }
        sb.append((i + 1)).append(". ").append(n1).append(" ").append(op).append(" ").append(n2).append(" = \n");
        Question question = new Question(n1 + " " + op + " " + n2 + " =", 0, expectedResult);
        questionList.add(question);
    }
    questionArea.setText(sb.toString());
}

private void checkAnswers() {
    correctCount = 0;
    wrongCount = 0;
    for (int i = 0; i < 30; i++) {
        int userAnswer;
        try {
            userAnswer = Integer.parseInt(answerFields[i].getText());
            if (userAnswer == questionList.get(i).getExpectedAnswer()) {
                correctCount++;
            } else {
                wrongCount++;
            }
        } catch (NumberFormatException ex) {
            wrongCount++;
        }
    }
}

private int getDivisor(int n1, Random random) {
    int divisor;
    do {
        divisor = random.nextInt(99)+1;
    } while (n1 % divisor!= 0);
    return divisor;
}

private void showFullResults() {
    double totalQuestions = 30.0;
    double correct = correctCount;
    double accuracy = (correct * 100 / totalQuestions);
    DecimalFormat df = new DecimalFormat("0.00");
    StringBuilder resultMessage = new StringBuilder();
    resultMessage.append("错题数：").append(wrongCount).append("\n");
    resultMessage.append("正确率：").append(df.format(accuracy)).append("%\n");
    resultMessage.append("题目\t\t用户答案\t正确答案\n");
    for (Question question : questionList) {
        int index = questionList.indexOf(question);
        resultMessage.append(question.getQuestion()).append("\t\t");
        resultMessage.append(answerFields[index].getText()).append("\t ");
        resultMessage.append(question.getExpectedAnswer()).append("\n");
    }
    JOptionPane.showMessageDialog(null, resultMessage.toString());
}


public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        @Override
        public void run() {
            Main quiz = new Main();
            quiz.setVisible(true);
        }
    });
}

}

class Question {
private String question;
private int userAnswer;
private int expectedAnswer;

public Question(String question, int userAnswer, int expectedAnswer) {
    this.question = question;
    this.userAnswer = userAnswer;
    this.expectedAnswer = expectedAnswer;
}

public String getQuestion() {
    return question;
}

public int getUserAnswer() {
    return userAnswer;
}

public int getExpectedAnswer() {
    return expectedAnswer;
}

}