src/main/java/com/mathquiz/model/ChoiceQuestion.java

@@ -1,141 +0,0 @@
-package com.mathquiz.model;
-
-import java.util.List;
-import java.util.Objects;
-import java.util.UUID;
-
-/**
- * 选择题模型类
- * 表示一道完整的数学选择题，包含题干、选项、正确答案等信息
- */
-public class ChoiceQuestion {
-
-    /**
-     * 题目唯一ID（UUID生成）
-     */
-    private String questionId;
-
-    /**
-     * 所属学段（小学 / 初中 / 高中）
-     */
-    private Grade grade;
-
-    /**
-     * 题干内容，例如："2 + 3 × (4 - 1) = ?"
-     */
-    private String questionContent;
-
-    /**
-     * 选项列表，固定4个选项，顺序已随机打乱
-     * 格式示例：["11", "10", "13", "9"]
-     */
-    private List<String> options;
-
-    /**
-     * 正确答案标识，取值为 "A"、"B"、"C" 或 "D"
-     */
-    private String correctAnswer;
-
-    // ---------------- 构造函数 ----------------
-
-    /**
-     * 默认构造函数（用于 JSON 反序列化）
-     */
-    public ChoiceQuestion() {}
-
-    /**
-     * 全参构造函数
-     */
-    public ChoiceQuestion(String questionId, Grade grade, String questionContent,
-                          List<String> options, String correctAnswer) {
-        this.questionId = questionId;
-        this.grade = grade;
-        this.questionContent = questionContent;
-        this.options = options;
-        this.correctAnswer = correctAnswer;
-    }
-
-    // ---------------- 静态工厂方法 ----------------
-
-    /**
-     * 创建一道新题目，自动分配 UUID 作为 questionId
-     *
-     * @param grade            年级
-     * @param questionContent  题干
-     * @param options          4个选项（顺序应已打乱）
-     * @param correctAnswer    正确答案（"A"-"D"）
-     * @return 新的 ChoiceQuestion 实例
-     */
-    public static ChoiceQuestion of(Grade grade, String questionContent,
-                                    List<String> options, String correctAnswer) {
-        return new ChoiceQuestion(UUID.randomUUID().toString(), grade, questionContent, options, correctAnswer);
-    }
-
-    // ---------------- Getter & Setter ----------------
-
-    public String getQuestionId() {
-        return questionId;
-    }
-
-    public void setQuestionId(String questionId) {
-        this.questionId = questionId;
-    }
-
-    public Grade getGrade() {
-        return grade;
-    }
-
-    public void setGrade(Grade grade) {
-        this.grade = grade;
-    }
-
-    public String getQuestionContent() {
-        return questionContent;
-    }
-
-    public void setQuestionContent(String questionContent) {
-        this.questionContent = questionContent;
-    }
-
-    public List<String> getOptions() {
-        return options;
-    }
-
-    public void setOptions(List<String> options) {
-        this.options = options;
-    }
-
-    public String getCorrectAnswer() {
-        return correctAnswer;
-    }
-
-    public void setCorrectAnswer(String correctAnswer) {
-        this.correctAnswer = correctAnswer;
-    }
-
-    // ---------------- Object 方法 ----------------
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-        ChoiceQuestion that = (ChoiceQuestion) o;
-        return Objects.equals(questionId, that.questionId);
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(questionId);
-    }
-
-    @Override
-    public String toString() {
-        return "ChoiceQuestion{" +
-                "questionId='" + questionId + '\'' +
-                ", grade=" + grade +
-                ", questionContent='" + questionContent + '\'' +
-                ", options=" + options +
-                ", correctAnswer='" + correctAnswer + '\'' +
-                '}';
-    }
-}

src/main/java/com/mathquiz/model/Grade.java

@@ -1,27 +0,0 @@
-package com.mathquiz.model;
-
-/**
- * 年级枚举，表示小学、初中、高中三个学段
- */
-
-public enum Grade {
-    PRIMARY("小学", 1),
-    JUNIOR("初中", 2),
-    SENIOR("高中", 3);
-
-    private final String displayName;
-    private final int level;
-
-    Grade(String displayName, int level) {
-        this.displayName = displayName;
-        this.level = level;
-    }
-
-    public String getDisplayName() {
-        return displayName;
-    }
-
-    public int getLevel() {
-        return level;
-    }
-}

src/main/java/com/mathquiz/model/User.java

@@ -1,52 +0,0 @@
-package com.mathquiz.model;
-
-/**
- * 用户类
- */
-
-public class User {
-    private String name;
-    private String email;
-    private String encryptedPwd;
-    private Grade grade;
-
-    public User() {}
-
-    public User(String email, String encryptedPwd) {
-        this.email = email;
-        this.encryptedPwd = encryptedPwd;
-    }
-
-    // Getter & Setter
-    public java.lang.String getName() {
-        return name;
-    }
-
-    public void setName(java.lang.String name) {
-        this.name = name;
-    }
-
-    public java.lang.String getEmail() {
-        return email;
-    }
-
-    public void setEmail(java.lang.String email) {
-        this.email = email;
-    }
-
-    public java.lang.String getEncryptedPwd() {
-        return encryptedPwd;
-    }
-
-    public void setEncryptedPwd(java.lang.String encryptedPwd) {
-        this.encryptedPwd = encryptedPwd;
-    }
-
-    public Grade getGrade() {
-        return grade;
-    }
-
-    public void setGrade(Grade grade) {
-        this.grade = grade;
-    }
-}

src/main/java/com/mathquiz/ui/GradeSelectPanel.java

@@ -0,0 +1,58 @@
+package com.mathquiz.ui;
+
+import com.mathquiz.model.Grade;
+import com.mathquiz.service.QuizService;
+import javafx.geometry.Insets;
+import javafx.scene.control.Button;
+import javafx.scene.control.TextInputDialog;
+import javafx.scene.layout.VBox;
+
+public class GradeSelectPanel extends VBox {
+
+    public GradeSelectPanel(MainWindow mainWindow) {
+        setPadding(new Insets(20));
+        setSpacing(20);
+
+        getChildren().addAll(
+                new Button("小学") {{
+                    setOnAction(e -> startQuiz(mainWindow, Grade.PRIMARY));
+                }},
+                new Button("初中") {{
+                    setOnAction(e -> startQuiz(mainWindow, Grade.JUNIOR));
+                }},
+                new Button("高中") {{
+                    setOnAction(e -> startQuiz(mainWindow, Grade.SENIOR));
+                }},
+                new Button("修改密码") {{
+                    setOnAction(e -> mainWindow.showPasswordModifyPanel());
+                }}
+        );
+    }
+
+    private void startQuiz(MainWindow mainWindow, Grade grade) {
+        TextInputDialog dialog = new TextInputDialog("20");
+        dialog.setTitle("题目数量");
+        dialog.setHeaderText("请输入题目数量（10-30）");
+        dialog.setContentText("数量:");
+
+        dialog.showAndWait().ifPresent(input -> {
+            try {
+                int count = Integer.parseInt(input);
+                if (count < 10 || count > 30) {
+                    throw new NumberFormatException();
+                }
+
+                // 创建 QuizService（未来可注入）
+                QuizService quizService = new QuizService(grade, mainWindow.getFileIOService());
+                var questions = quizService.generateQuestions(
+                        mainWindow.getCurrentUser().getEmail(), count
+                );
+
+                mainWindow.showQuizPanel(questions, quizService);
+
+            } catch (NumberFormatException e) {
+                new Alert(Alert.AlertType.ERROR, "请输入10-30之间的整数").showAndWait();
+            }
+        });
+    }
+}

src/main/java/com/mathquiz/ui/LoginPanel.java

@@ -0,0 +1,44 @@
+package com.mathquiz.ui;
+
+import com.mathquiz.model.User;
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+
+public class LoginPanel extends VBox {
+
+    private final TextField emailField = new TextField();
+    private final PasswordField pwdField = new PasswordField();
+
+    public LoginPanel(MainWindow mainWindow) {
+        setPadding(new Insets(20));
+        setSpacing(10);
+
+        getChildren().addAll(
+                new Label("登录"),
+                new Label("邮箱:"),
+                emailField,
+                new Label("密码:"),
+                pwdField,
+                new Button("登录") {{
+                    setOnAction(e -> loginAction(mainWindow));
+                }},
+                new Hyperlink("没有账号？去注册") {{
+                    setOnAction(e -> mainWindow.showRegisterPanel());
+                }}
+        );
+    }
+
+    private void loginAction(MainWindow mainWindow) {
+        String email = emailField.getText().trim();
+        String password = pwdField.getText();
+
+        User user = mainWindow.getUserService().login(email, password);
+        if (user != null) {
+            mainWindow.setCurrentUser(user);
+            mainWindow.showGradeSelectPanel();
+        } else {
+            new Alert(Alert.AlertType.ERROR, "邮箱或密码错误").showAndWait();
+        }
+    }
+}

src/main/java/com/mathquiz/ui/MainWindow.java

@@ -0,0 +1,77 @@
+package com.mathquiz.ui;
+
+import com.mathquiz.model.User;
+import com.mathquiz.service.*;
+import javafx.scene.layout.BorderPane;
+import javafx.stage.Stage;
+
+/**
+ * 主窗口控制器，持有所有服务引用和当前用户状态
+ * 所有 UI 面板通过此窗口切换
+ */
+public class MainWindow extends BorderPane {
+
+    // 服务层引用（便于后期替换实现）
+    private final UserService userService;
+    private final FileIOService fileIOService;
+    private User currentUser;
+
+    public MainWindow(Stage primaryStage) {
+        // 初始化服务（未来可替换为 DI 容器）
+        this.fileIOService = new FileIOService();
+        this.userService = new UserService(fileIOService);
+
+        // 默认显示登录页
+        showLoginPanel();
+    }
+
+    // ---------------- 公共方法：面板切换 ----------------
+
+    public void showPanel(javafx.scene.layout.Pane panel) {
+        this.setCenter(panel);
+    }
+
+    public void showLoginPanel() {
+        showPanel(new LoginPanel(this));
+    }
+
+    public void showRegisterPanel() {
+        showPanel(new RegisterPanel(this));
+    }
+
+    public void showPasswordModifyPanel() {
+        if (currentUser != null) {
+            showPanel(new PasswordModifyPanel(this, currentUser.getEmail()));
+        }
+    }
+
+    public void showGradeSelectPanel() {
+        showPanel(new GradeSelectPanel(this));
+    }
+
+    public void showQuizPanel(java.util.List<com.mathquiz.model.ChoiceQuestion> questions, QuizService quizService) {
+        showPanel(new QuizPanel(this, questions, quizService));
+    }
+
+    public void showResultPanel(int score, Runnable onContinue) {
+        showPanel(new ResultPanel(this, score, onContinue));
+    }
+
+    // ---------------- Getter ----------------
+
+    public UserService getUserService() {
+        return userService;
+    }
+
+    public FileIOService getFileIOService() {
+        return fileIOService;
+    }
+
+    public User getCurrentUser() {
+        return currentUser;
+    }
+
+    public void setCurrentUser(User user) {
+        this.currentUser = user;
+    }
+}

src/main/java/com/mathquiz/ui/PasswordModifyPanel.java

@@ -0,0 +1,46 @@
+package com.mathquiz.ui;
+
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+
+public class PasswordModifyPanel extends VBox {
+
+    private final String email;
+    private final PasswordField oldPwdField = new PasswordField();
+    private final PasswordField newPwd1Field = new PasswordField();
+    private final PasswordField newPwd2Field = new PasswordField();
+
+    public PasswordModifyPanel(MainWindow mainWindow, String email) {
+        this.email = email;
+        setPadding(new Insets(20));
+        setSpacing(10);
+
+        getChildren().addAll(
+                new Label("修改密码"),
+                new Label("原密码:"),
+                oldPwdField,
+                new Label("新密码（6-10位，含大小写+数字）:"),
+                newPwd1Field,
+                new Label("确认新密码:"),
+                newPwd2Field,
+                new Button("确认修改") {{
+                    setOnAction(e -> changePassword(mainWindow));
+                }},
+                new Button("返回") {{
+                    setOnAction(e -> mainWindow.showGradeSelectPanel());
+                }}
+        );
+    }
+
+    private void changePassword(MainWindow mainWindow) {
+        boolean success = mainWindow.getUserService()
+                .changePassword(email, oldPwdField.getText(), newPwd1Field.getText(), newPwd2Field.getText());
+        if (success) {
+            new Alert(Alert.AlertType.INFORMATION, "密码修改成功！").showAndWait();
+            mainWindow.showGradeSelectPanel();
+        } else {
+            new Alert(Alert.AlertType.ERROR, "原密码错误或新密码不符合要求").showAndWait();
+        }
+    }
+}

src/main/java/com/mathquiz/ui/QuizPanel.java

@@ -0,0 +1,67 @@
+package com.mathquiz.ui;
+
+import com.mathquiz.model.ChoiceQuestion;
+import com.mathquiz.service.QuizService;
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class QuizPanel extends VBox {
+
+    private final List<ChoiceQuestion> questions;
+    private final List<String> userAnswers = new ArrayList<>();
+    private final QuizService quizService;
+    private final MainWindow mainWindow;
+    private int currentIndex = 0;
+
+    public QuizPanel(MainWindow mainWindow, List<ChoiceQuestion> questions, QuizService quizService) {
+        this.mainWindow = mainWindow;
+        this.questions = questions;
+        this.quizService = quizService;
+        setPadding(new Insets(20));
+        showQuestion(currentIndex);
+    }
+
+    private void showQuestion(int index) {
+        getChildren().clear();
+        ChoiceQuestion q = questions.get(index);
+
+        getChildren().add(new Label("第 " + (index + 1) + " 题 / " + questions.size()));
+        getChildren().add(new Label(q.getQuestionContent()));
+
+        ToggleGroup group = new ToggleGroup();
+        for (int i = 0; i < 4; i++) {
+            RadioButton rb = new RadioButton(
+                    (char)('A' + i) + ". " + q.getOptions().get(i)
+            );
+            rb.setToggleGroup(group);
+            getChildren().add(rb);
+        }
+
+        Button submitBtn = new Button("提交");
+        submitBtn.setOnAction(e -> {
+            RadioButton selected = (RadioButton) group.getSelectedToggle();
+            if (selected != null) {
+                String answer = selected.getText().substring(0, 1); // "A"
+                userAnswers.add(answer);
+
+                if (index + 1 < questions.size()) {
+                    showQuestion(index + 1);
+                } else {
+                    int score = quizService.calculateScore(questions, userAnswers);
+                    Runnable onContinue = () -> {
+                        quizService.savePaper(mainWindow.getCurrentUser().getEmail(), questions);
+                    };
+                    mainWindow.showResultPanel(score, onContinue);
+                }
+            } else {
+                new Alert(Alert.AlertType.WARNING, "请选择一个选项").showAndWait();
+            }
+        });
+
+        getChildren().add(submitBtn);
+    }
+}

src/main/java/com/mathquiz/ui/RegisterPanel.java

@@ -0,0 +1,80 @@
+package com.mathquiz.ui;
+
+import com.mathquiz.util.EmailUtil;
+import javafx.geometry.Insets;
+import javafx.scene.control.*;
+import javafx.scene.layout.VBox;
+
+/**
+ * 注册面板
+ */
+public class RegisterPanel extends VBox {
+
+    private final TextField emailField = new TextField();
+    private final TextField codeField = new TextField();
+    private final PasswordField pwd1Field = new PasswordField();
+    private final PasswordField pwd2Field = new PasswordField();
+
+    public RegisterPanel(MainWindow mainWindow) {
+        setPadding(new Insets(20));
+        setSpacing(10);
+
+        getChildren().addAll(
+                new Label("注册"),
+                new Label("邮箱:"),
+                emailField,
+                new Button("发送注册码") {{
+                    setOnAction(e -> sendCodeAction(mainWindow));
+                }},
+                new Label("注册码:"),
+                codeField,
+                new Label("密码（6-10位，含大小写+数字）:"),
+                pwd1Field,
+                new Label("确认密码:"),
+                pwd2Field,
+                new Button("完成注册") {{
+                    setOnAction(e -> registerAction(mainWindow));
+                }},
+                new Hyperlink("已有账号？去登录") {{
+                    setOnAction(e -> mainWindow.showLoginPanel());
+                }}
+        );
+    }
+
+    private void sendCodeAction(MainWindow mainWindow) {
+        String email = emailField.getText().trim();
+        if (email.isEmpty() || !EmailUtil.isValidEmail(email)) {
+            showAlert("请输入有效的邮箱地址");
+            return;
+        }
+        // 调用服务层
+        boolean sent = mainWindow.getUserService().sendRegistrationCode(email);
+        if (sent) {
+            showAlert("注册码已发送（模拟）");
+        }
+    }
+
+    private void registerAction(MainWindow mainWindow) {
+        String email = emailField.getText().trim();
+        String code = codeField.getText().trim();
+        String pwd1 = pwd1Field.getText();
+        String pwd2 = pwd2Field.getText();
+
+        if (!mainWindow.getUserService().verifyCode(email, code)) {
+            showAlert("注册码错误");
+            return;
+        }
+
+        boolean success = mainWindow.getUserService().setPassword(email, pwd1, pwd2);
+        if (success) {
+            showAlert("注册成功！");
+            mainWindow.showGradeSelectPanel();
+        } else {
+            showAlert("密码不符合要求（6-10位，含大小写字母和数字）");
+        }
+    }
+
+    private void showAlert(String message) {
+        new Alert(Alert.AlertType.INFORMATION, message).showAndWait();
+    }
+}

src/main/java/com/mathquiz/ui/ResultPanel.java

@@ -0,0 +1,32 @@
+package com.mathquiz.ui;
+
+import javafx.geometry.Insets;
+import javafx.scene.control.Alert;
+import javafx.scene.control.Button;
+import javafx.scene.control.Label;
+import javafx.scene.layout.VBox;
+
+public class ResultPanel extends VBox {
+
+    public ResultPanel(MainWindow mainWindow, int score, Runnable onContinue) {
+        setPadding(new Insets(20));
+        setSpacing(20);
+
+        getChildren().addAll(
+                new Label("答题结束！"),
+                new Label("您的得分: " + score + " 分"),
+                new Button("继续做题") {{
+                    setOnAction(e -> {
+                        onContinue.run(); // 保存试卷
+                        mainWindow.showGradeSelectPanel();
+                    });
+                }},
+                new Button("退出") {{
+                    setOnAction(e -> {
+                        mainWindow.setCurrentUser(null);
+                        mainWindow.showLoginPanel();
+                    });
+                }}
+        );
+    }
+}

src/main/java/com/mathquiz/util/EmailUtil.java

@@ -1,109 +0,0 @@
-package com.util;
-
-/**
- * 邮件工具类
- * 用于发送注册码邮件（可选功能）
- * 注意：当前项目需求中，注册码是直接显示在界面上的，
- * 不需要发送邮件，所以这个类暂时保留为空实现。
- * 如果将来需要发送邮件，可以使用JavaMail库实现。
- */
-public class EmailUtil {
-
-    /**
-     * 发送注册码邮件（预留接口）
-     * @param toEmail 收件人邮箱
-     * @param registrationCode 注册码
-     * @return true表示发送成功
-     */
-    public static boolean sendRegistrationCode(String toEmail, String registrationCode) {
-        // TODO: 暂不实现邮件发送功能
-        // 原因：项目需求是直接在界面显示注册码，不需要发邮件
-
-        System.out.println("【模拟】发送注册码邮件");
-        System.out.println("收件人: " + toEmail);
-        System.out.println("注册码: " + registrationCode);
-
-        return true;
-    }
-
-    /**
-     * 发送密码重置邮件（预留接口）
-     * @param toEmail 收件人邮箱
-     * @param newPassword 新密码
-     * @return true表示发送成功
-     */
-    public static boolean sendPasswordReset(String toEmail, String newPassword) {
-        // TODO: 将来如果需要"找回密码"功能，可以在这里实现
-
-        System.out.println("【模拟】发送密码重置邮件");
-        System.out.println("收件人: " + toEmail);
-        System.out.println("新密码: " + newPassword);
-
-        return true;
-    }
-
-    /**
-     * 验证邮箱格式
-     * @param email 邮箱地址
-     * @return true表示格式正确
-     */
-    public static boolean isValidEmail(String email) {
-        if (email == null || email.trim().isEmpty()) {
-            return false;
-        }
-
-        // 简单的邮箱格式验证
-        String emailRegex = "^[A-Za-z0-9+_.-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}$";
-        return email.matches(emailRegex);
-    }
-}
-
-/*
- * 如果将来需要真正实现邮件发送，可以参考以下代码：
- *
- * 1. 在pom.xml添加依赖：
- * <dependency>
- *     <groupId>javax.mail</groupId>
- *     <artifactId>javax.mail-api</artifactId>
- *     <version>1.6.2</version>
- * </dependency>
- * <dependency>
- *     <groupId>com.sun.mail</groupId>
- *     <artifactId>javax.mail</artifactId>
- *     <version>1.6.2</version>
- * </dependency>
- *
- * 2. 实现代码示例：
- *
- * import javax.mail.*;
- * import javax.mail.internet.*;
- * import java.util.Properties;
- *
- * public static boolean sendEmail(String toEmail, String subject, String content) {
- *     try {
- *         Properties props = new Properties();
- *         props.put("mail.smtp.auth", "true");
- *         props.put("mail.smtp.starttls.enable", "true");
- *         props.put("mail.smtp.host", "smtp.qq.com");
- *         props.put("mail.smtp.port", "587");
- *
- *         Session session = Session.getInstance(props, new Authenticator() {
- *             protected PasswordAuthentication getPasswordAuthentication() {
- *                 return new PasswordAuthentication("your-email@qq.com", "your-password");
- *             }
- *         });
- *
- *         Message message = new MimeMessage(session);
- *         message.setFrom(new InternetAddress("your-email@qq.com"));
- *         message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(toEmail));
- *         message.setSubject(subject);
- *         message.setText(content);
- *
- *         Transport.send(message);
- *         return true;
- *     } catch (Exception e) {
- *         e.printStackTrace();
- *         return false;
- *     }
- * }
- */

src/main/java/com/mathquiz/util/FileUtils.java

@@ -1,111 +0,0 @@
-package com.util;
-
-import java.io.*;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.*;
-
-/**
- * 文件操作工具类
- * 提供文件读写、目录创建等常用操作
- */
-public class FileUtils {
-
-    /**
-     * 读取文件内容为字符串
-     * @param filePath 文件路径
-     * @return 文件内容
-     * @throws IOException 读取失败时抛出
-     */
-    public static String readFileToString(String filePath) throws IOException {
-        return Files.readString(Paths.get(filePath), StandardCharsets.UTF_8);
-    }
-
-    /**
-     * 写入字符串到文件
-     * @param filePath 文件路径
-     * @param content 要写入的内容
-     * @throws IOException 写入失败时抛出
-     */
-    public static void writeStringToFile(String filePath, String content) throws IOException {
-        Files.writeString(Paths.get(filePath), content, StandardCharsets.UTF_8);
-    }
-
-    /**
-     * 创建目录（如果不存在）
-     * @param dirPath 目录路径
-     * @throws IOException 创建失败时抛出
-     */
-    public static void createDirectoryIfNotExists(String dirPath) throws IOException {
-        Path path = Paths.get(dirPath);
-        if (!Files.exists(path)) {
-            Files.createDirectories(path);
-        }
-    }
-
-    /**
-     * 检查文件是否存在
-     * @param filePath 文件路径
-     * @return true表示存在
-     */
-    public static boolean exists(String filePath) {
-        return Files.exists(Paths.get(filePath));
-    }
-
-    /**
-     * 删除文件
-     * @param filePath 文件路径
-     * @return true表示删除成功
-     */
-    public static boolean deleteFile(String filePath) {
-        try {
-            return Files.deleteIfExists(Paths.get(filePath));
-        } catch (IOException e) {
-            e.printStackTrace();
-            return false;
-        }
-    }
-
-    /**
-     * 获取目录下所有文件
-     * @param dirPath 目录路径
-     * @return 文件数组
-     */
-    public static File[] listFiles(String dirPath) {
-        File dir = new File(dirPath);
-        if (dir.exists() && dir.isDirectory()) {
-            return dir.listFiles();
-        }
-        return new File[0];
-    }
-
-    /**
-     * 追加内容到文件末尾
-     * @param filePath 文件路径
-     * @param content 要追加的内容
-     * @throws IOException 追加失败时抛出
-     */
-    public static void appendToFile(String filePath, String content) throws IOException {
-        Files.writeString(Paths.get(filePath), content, StandardCharsets.UTF_8,
-                StandardOpenOption.CREATE, StandardOpenOption.APPEND);
-    }
-
-    /**
-     * 复制文件
-     * @param sourcePath 源文件路径
-     * @param targetPath 目标文件路径
-     * @throws IOException 复制失败时抛出
-     */
-    public static void copyFile(String sourcePath, String targetPath) throws IOException {
-        Files.copy(Paths.get(sourcePath), Paths.get(targetPath), StandardCopyOption.REPLACE_EXISTING);
-    }
-
-    /**
-     * 获取文件大小（字节）
-     * @param filePath 文件路径
-     * @return 文件大小
-     * @throws IOException 获取失败时抛出
-     */
-    public static long getFileSize(String filePath) throws IOException {
-        return Files.size(Paths.get(filePath));
-    }
-}

src/main/java/com/mathquiz/util/PasswordValidator.java

@@ -1,102 +0,0 @@
-package com.util;
-
-import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
-
-/**
- * 密码验证和加密工具类
- * 提供密码格式验证、加密、匹配等功能
- */
-public class PasswordValidator {
-
-    /**
-     * 验证密码格式：6-10位，包含字母和数字
-     * @param password 待验证的密码
-     * @return true表示格式正确
-     */
-    public static boolean isValid(String password) {
-        if (password == null || password.length() < 6 || password.length() > 10) {
-            return false;
-        }
-
-        boolean hasLetter = password.matches("^(?=.*[a-z])(?=.*[A-Z]).*$");
-        boolean hasDigit = password.matches(".*\\d.*");
-
-        return hasLetter && hasDigit;
-    }
-
-    /**
-     * 使用SHA-256加密密码
-     * @param password 明文密码
-     * @return 加密后的密码（16进制字符串）
-     */
-    public static String encrypt(String password) {
-        try {
-            MessageDigest digest = MessageDigest.getInstance("SHA-256");
-            byte[] hash = digest.digest(password.getBytes());
-            StringBuilder hexString = new StringBuilder();
-
-            for (byte b : hash) {
-                String hex = Integer.toHexString(0xff & b);
-                if (hex.length() == 1) {
-                    hexString.append('0');
-                }
-                hexString.append(hex);
-            }
-
-            return hexString.toString();
-        } catch (NoSuchAlgorithmException e) {
-            throw new RuntimeException("SHA-256算法不可用", e);
-        }
-    }
-
-    /**
-     * 验证密码是否匹配
-     * @param plainPassword 明文密码
-     * @param encryptedPassword 加密后的密码
-     * @return true表示匹配
-     */
-    public static boolean matches(String plainPassword, String encryptedPassword) {
-        return encrypt(plainPassword).equals(encryptedPassword);
-    }
-
-    /**
-     * 生成6-10位随机注册码（包含字母和数字）
-     * @return 注册码
-     */
-    public static String generateRegistrationCode() {
-        String chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
-        int length = 6 + (int) (Math.random() * 5); // 6-10位
-
-        StringBuilder code = new StringBuilder();
-
-        // 确保至少有一个字母
-        code.append(chars.charAt((int) (Math.random() * 52)));
-        // 确保至少有一个数字
-        code.append(chars.charAt(52 + (int) (Math.random() * 10)));
-
-        // 填充剩余字符
-        for (int i = 2; i < length; i++) {
-            code.append(chars.charAt((int) (Math.random() * chars.length())));
-        }
-
-        // 打乱字符顺序
-        return shuffleString(code.toString());
-    }
-
-    /**
-     * 打乱字符串
-     * @param str 原字符串
-     * @return 打乱后的字符串
-     */
-    private static String shuffleString(String str) {
-        char[] chars = str.toCharArray();
-        for (int i = chars.length - 1; i > 0; i--) {
-            int j = (int) (Math.random() * (i + 1));
-            char temp = chars[i];
-            chars[i] = chars[j];
-            chars[j] = temp;
-        }
-        return new String(chars);
-    }
-}

src/main/java/com/mathquiz/util/RandomUtils.java

@@ -1,69 +0,0 @@
-package com.util;
-
-import java.util.Collections;
-import java.util.List;
-import java.util.Random;
-
-//各种随机数生成
-public class RandomUtils {
-    private static final Random random = new Random();
-
-
-    //生成[min, max]范围内的随机整数（包含边界）
-    public static int nextInt(int min, int max) {
-        if (min > max) {
-            throw new IllegalArgumentException("min不能大于max");
-        }
-        return min + random.nextInt(max - min + 1);
-    }
-
-
-    //从数组中随机选择一个元素(模板类）
-    public static <T> T randomChoice(T[] array) {
-        if (array == null || array.length == 0) {
-            throw new IllegalArgumentException("数组不能为空");
-        }
-        return array[random.nextInt(array.length)];
-    }
-
-
-    //从列表中随机选择一个元素
-    public static <T> T randomChoice(List<T> list) {
-        if (list == null || list.isEmpty()) {
-            throw new IllegalArgumentException("列表不能为空");
-        }
-        return list.get(random.nextInt(list.size()));
-    }
-
-    /**
-     * 打乱列表顺序
-     * @param list 要打乱的列表
-     */
-    public static <T> void shuffle(List<T> list) {
-        Collections.shuffle(list, random);
-    }
-
-
-    //生成指定范围内的随机双精度浮点数
-    public static double nextDouble(double min, double max) {
-        if (min > max) {
-            throw new IllegalArgumentException("min不能大于max");
-        }
-        return min + (max - min) * random.nextDouble();
-    }
-
-
-    //生成随机布尔值
-    public static boolean nextBoolean() {
-        return random.nextBoolean();
-    }
-
-    //按概率返回true（题目生成概率）
-    //示例：probability(0.7) 有70%概率返回true
-    public static boolean probability(double probability) {
-        if (probability < 0.0 || probability > 1.0) {
-            throw new IllegalArgumentException("概率必须在0.0-1.0之间");
-        }
-        return random.nextDouble() < probability;
-    }
-}