添加 'doc/README.MD'

Reviewed-on: #2

.idea/.gitignore

@@ -0,0 +1,8 @@
+# 默认忽略的文件
+/shelf/
+/workspace.xml
+# 基于编辑器的 HTTP 客户端请求
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/misc.xml

@@ -0,0 +1,6 @@
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.idea/modules.xml

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+    "node.js.selected.package.eslint": "(autodetect)",
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+    "project.structure.last.edited": "模块",
+    "project.structure.proportion": "0.0",
+    "project.structure.side.proportion": "0.2",
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README.md

@@ -1,2 +0,0 @@
-# MathEaxmApp
-

doc/README.MD

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+# 数学题目生成器 (图形化界面版) 项目说明文档
+
+
+
+
+
+## 1. 项目概述
+
+
+
+该项目是一个功能完善的、拥有现代化图形用户界面（GUI）的桌面应用。它旨在为不同年级（小学、初中、高中）的学生提供一个集用户管理、题目练习、自动评分和历史存档于一体的综合性数学学习平台。用户可以通过友好的界面进行注册、登录、选择难度、进行交互式答题，并通过真实的电子邮件接收验证码，确保了账户的安全性。
+
+
+
+## 2. 项目功能
+
+
+
+
+
+### 2.1 用户管理
+
+
+
+- **用户注册**：提供邮箱和自定义用户名进行注册。系统会向用户提供的邮箱发送一封包含**真实6位验证码**的邮件，用户需凭此验证码完成注册。
+- **密码安全**：支持用户设置符合强度要求（6-10位，含大小写字母和数字）的密码，并在登录状态下安全地修改密码。
+- **双模式登录**：系统支持用户使用**邮箱**或**用户名**两种方式配合密码进行登录，更加便捷。
+
+
+
+### 2.2 题目与考试
+
+
+
+- **智能题目生成**：根据用户选择的年级，动态生成不同复杂度的题目。题目包含2-5个操作数，并能智能地添加有意义的单层或双重括号。
+- **交互式答题**：题目以选择题形式在界面中逐题展示，用户可通过鼠标点击进行选择。
+- **双向导航**：在答题过程中，用户可以使用“上一题”、“下一题”按钮在题目之间自由切换，检查并修改之前的答案。
+- **提前交卷**：用户可在答题未完成时选择提前交卷，系统会进行确认提醒，并根据已完成的题目计分。
+- **自动评分与存档**：答题结束后，系统会立即计算得分（百分制）并展示。同时，每一次生成的完整试卷（包含题目、选项、正确答案）都会自动保存到以该用户命名的专属文件夹中，便于后续复习。
+
+
+
+### 2.3 用户界面
+
+
+
+- **现代化图形界面**：基于 `Java Swing` 和 `FlatLaf` UI库构建，提供了一个美观、清爽、响应流畅的桌面应用体验。
+- **多视图切换**：拥有登录、注册、密码设置、主菜单、考试、分数等多个独立视图，流程清晰，操作直观。
+- **人性化交互**：答题界面提供实时进度条，导航按钮状态会根据当前题号自动更新，为用户提供清晰的操作指引。
+
+
+
+## 3. 系统架构
+
+
+
+项目采用业界标准的 **MVC (Model-View-Controller)** 设计模式，确保了代码的高度解耦、可维护性和可扩展性。
+
+
+
+### 3.1 模型 (Model)
+
+
+
+负责处理数据和业务逻辑，完全独立于界面。
+
+- **`model` 包**: 定义核心数据结构，如 `User`, `Question`。
+- **`service` 包**: 实现所有后台服务逻辑，如 `UserManager` (用户管理)、`ExamManager` (考试管理) 和 `EmailService` (邮件发送服务)。
+
+
+
+### 3.2 视图 (View)
+
+
+
+负责渲染用户界面，是用户直接交互的层面。
+
+- **`view` 包**: 包含了所有的UI界面类，如 `LoginView`, `ExamView`, `MainMenuView` 等。这些类只负责“显示”，不包含任何业务逻辑。
+
+
+
+### 3.3 控制器 (Controller)
+
+
+
+作为模型和视图之间的桥梁，调度整个应用程序。
+
+- **`controller` 包**: 核心类 `AppController` 在此包中。它接收视图层传来的用户操作，调用模型层处理，并根据结果更新视图层的显示。
+
+
+
+## 4. 代码详解
+
+
+
+### 4.1 题目生成规则
+
+所有生成器都经过重构，能够生成包含2-5个操作数及有意义括号的复杂表达式。
+
+#### 4.1.1 `PrimaryQuestionGenerator`
+
+为小学用户生成复杂的四则运算题目，智能地使用括号改变运算优先级。
+
+```
+((10 + 5) × 3) - 12
+```
+
+#### 4.1.2 `JuniorQuestionGenerator`
+
+在复杂表达式中，确保至少包含一个平方 (`^2`) 或开根号 (`√`) 运算。
+
+```
+(8 + √ (49)) × 3^2
+```
+
+#### 4.1.3 `SeniorQuestionGenerator`
+
+在复杂表达式中，确保至少包含一个三角函数 (`sin`, `cos`, `tan`)，并已修复 `tan(90°)` 的bug。
+
+```
+5 × (sin(30°) + 4)
+```
+
+
+
+### 4.2 题目格式与计分
+
+- 所有题目均为四选一的选择题。
+- 系统会智能判断正确答案是整数还是小数，并生成逻辑相符的干扰选项。
+- 计分方式为 `(答对题数 / 总题数) * 100`，结果四舍五入取整。
+
+## 5. 运行说明
+
+
+
+1. **启动程序** 运行 `Main.java` 类，启动图形化登录窗口。
+2. **用户注册/登录**
+   - 新用户点击“注册”，按照“输入邮箱/用户名 -> 发送验证邮件 -> 查收邮件验证码 -> 设置密码”的流程完成注册。
+   - 老用户可使用邮箱或用户名直接登录。
+3. **开始考试** 在主菜单选择题目难度和数量，点击“开始答题”进入考试界面。
+4. **答题过程** 通过“上一题”、“下一题”进行导航，随时可通过“交卷并评分”按钮结束考试。
+5. **查看分数** 交卷后，分数界面会显示本次得分和答题详情。用户可选择“再来一组”或“退出登录”。
+
+
+
+## 6. 代码结构
+
+
+
+```
+src/
+├── Main.java
+├── config.properties
+├── controller/
+│   └── AppController.java
+├── model/
+│   ├── Question.java
+│   ├── User.java
+│   └── UserType.java
+├── service/
+│   ├── EmailService.java
+│   ├── ExamManager.java
+│   ├── ExpressionEvaluator.java
+│   ├── UserManager.java
+│   ├── ValidationService.java
+│   └── generator/
+│       └── ... (5个题目生成器相关文件)
+└── view/
+    └── ... (8个界面视图相关文件)
+```
+
+
+
+## 7. 依赖与配置
+
+###  软件依赖 (JAR文件)
+
+本项目需要以下4个外部库文件，以下依赖库以添加至总项目lib文件夹中
+
+- **FlatLaf UI主题**: `flatlaf-3.4.1.jar`
+
+- **Jakarta Mail API**: `jakarta.mail-api-2.1.2.jar`
+
+- **Angus Mail (实现)**: `angus-mail-2.0.2.jar`
+
+- **Angus Activation (依赖)**: `angus-activation-2.0.2.jar`
+
+  
+
+### Windows 系统下运行步骤
+
+1. **配置 Java 22 编译环境**
+
+   确保系统已安装 Java 22 JDK 版本
+
+2. **设置控制台编码**
+
+   打开 cmd 命令行工具，使用以下指令执行 .jar 文件：
+
+   ```
+   java -jar .\MathExamApp.jar
+   ```
+
+   
+
+### Linux 系统下运行步骤
+
+1. **配置 Java 22 JDK 版本**
+
+   确保系统已安装 Java 22 JDK
+
+2. **运行程序**
+
+   使用以下指令执行程序：
+
+   java -jar MathExamApp.jar
+
+
+
+## 8. 注意事项
+
+
+
+1. **数据文件夹**：程序第一次成功注册用户或生成试卷后，会在程序运行的根目录下自动创建以下文件夹：
+   - `data/`：此文件夹包含 `users.txt` 文件，用于存储所有用户的账号和密码信息。
+   - `exams/`：此文件夹下会以每个用户的邮箱/用户名创建子文件夹，用于存放该用户所有历史试卷的 `.txt` 文件。
+2. **请勿删除**：上述两个文件夹是程序正常运行和数据持久化的关键。**请不要手动删除或修改这些文件夹及其中的内容**，否则将导致所有用户账号信息和历史试卷记录丢失，且无法恢复。

src/Main.java

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+import com.formdev.flatlaf.FlatLightLaf;
+import controller.AppController;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.UnsupportedLookAndFeelException;
+
+public class Main {
+    public static void main(String[] args) {
+        System.setProperty("awt.useSystemAAFontSettings", "on");
+        System.setProperty("swing.aatext", "true");
+
+        try {
+            UIManager.setLookAndFeel(new FlatLightLaf());
+        } catch (UnsupportedLookAndFeelException e) {
+            System.err.println("无法设置UI主题: " + e.getMessage());
+        }
+
+        SwingUtilities.invokeLater(AppController::new);
+    }
+}

src/MathEaxmApp.iml

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+<?xml version="1.0" encoding="UTF-8"?>
+<module type="JAVA_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$">
+      <sourceFolder url="file://$MODULE_DIR$" isTestSource="false" />
+    </content>
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

src/config.properties

@@ -0,0 +1,10 @@
+
+smtp.host=smtp.qq.com
+smtp.port=465
+smtp.ssl.enable=true
+smtp.auth=true
+
+
+mail.sender.email=2631495488@qq.com
+
+mail.sender.password=vdjvddhflexgdjfd

src/model/Question.java

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+package model;
+
+import java.util.List;
+
+public class Question {
+    private final String questionText;
+    private final List<String> options;
+    private final int correctOptionIndex;
+
+    public Question(String questionText, List<String> options, int correctOptionIndex) {
+        this.questionText = questionText;
+        this.options = options;
+        this.correctOptionIndex = correctOptionIndex;
+    }
+
+    public String getQuestionText() { return questionText; }
+    public List<String> getOptions() { return options; }
+    public int getCorrectOptionIndex() { return correctOptionIndex; }
+}

src/model/User.java

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+package model;
+
+public class User {
+    private final String email;
+    private final String username; // 新增字段
+    private String hashedPassword;
+    private UserType userType;
+
+    public User(String email, String username, String hashedPassword, UserType userType) {
+        this.email = email;
+        this.username = username;
+        this.hashedPassword = hashedPassword;
+        this.userType = userType;
+    }
+
+    public String getEmail() { return email; }
+    public String getUsername() { return username; } // 新增Getter
+    public String getHashedPassword() { return hashedPassword; }
+    public UserType getUserType() { return userType; }
+    public void setUserType(UserType userType) { this.userType = userType; }
+
+    public void setHashedPassword(String plainPassword) {
+        this.hashedPassword = Integer.toString(plainPassword.hashCode());
+    }
+
+    private void setHashedPasswordDirectly(String hashedPassword) {
+        this.hashedPassword = hashedPassword;
+    }
+
+    @Override
+    public String toString() {
+        // 新的4字段格式，用户名可以为空字符串
+        return String.join("|", email, username == null ? "" : username, hashedPassword, userType.name());
+    }
+
+
+    public static User fromString(String line) {
+        String[] parts = line.split("\\|");
+        User user = null;
+        if (parts.length == 4) { // 新格式: email|username|password|type
+            String email = parts[0];
+            String username = parts[1].isEmpty() ? null : parts[1];
+            String password = parts[2];
+            UserType type = UserType.valueOf(parts[3]);
+            user = new User(email, username, "", type);
+            user.setHashedPasswordDirectly(password);
+        } else if (parts.length == 3) { // 旧格式: email|password|type
+            String email = parts[0];
+            String password = parts[1];
+            UserType type = UserType.valueOf(parts[2]);
+            user = new User(email, null, "", type); // 旧用户没有用户名
+            user.setHashedPasswordDirectly(password);
+        }
+        return user;
+    }
+}

src/model/UserType.java

@@ -0,0 +1,17 @@
+package model;
+
+public enum UserType {
+    PRIMARY("小学"),
+    JUNIOR("初中"),
+    SENIOR("高中");
+
+    private final String displayName;
+
+    UserType(String displayName) {
+        this.displayName = displayName;
+    }
+
+    public String getDisplayName() {
+        return displayName;
+    }
+}

src/service/EmailService.java

@@ -0,0 +1,74 @@
+package service;
+
+import javax.mail.*;
+import javax.mail.internet.*;
+import javax.activation.*;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Properties;
+
+
+public class EmailService {
+
+    final Properties props = new Properties();
+    private final String senderEmail;
+    private final String senderPassword;
+
+    public EmailService() {
+
+        try (InputStream input = EmailService.class.getClassLoader().getResourceAsStream("config.properties")) {
+
+
+            if (input == null) {
+                System.err.println("致命错误：在类路径中找不到 config.properties 文件！");
+                System.err.println("请确认 'config.properties' 文件已放置在 'src' 文件夹根目录下。");
+                throw new RuntimeException("加载配置文件失败: config.properties not found in classpath");
+            }
+
+            props.load(input);
+
+        } catch (IOException e) {
+            System.err.println("错误：加载 config.properties 文件时发生IO错误！");
+            throw new RuntimeException("加载配置文件失败", e);
+        }
+
+        this.senderEmail = props.getProperty("mail.sender.email");
+        this.senderPassword = props.getProperty("mail.sender.password");
+    }
+
+
+    public void sendVerificationCode(String recipientEmail, String code) throws MessagingException {
+
+        Properties mailProps = new Properties();
+        mailProps.put("mail.smtp.host", props.getProperty("smtp.host"));
+        mailProps.put("mail.smtp.port", props.getProperty("smtp.port"));
+        mailProps.put("mail.smtp.ssl.enable", props.getProperty("smtp.ssl.enable"));
+        mailProps.put("mail.smtp.auth", props.getProperty("smtp.auth"));
+
+        Authenticator authenticator = new Authenticator() {
+            @Override
+            protected PasswordAuthentication getPasswordAuthentication() {
+                return new PasswordAuthentication(senderEmail, senderPassword);
+            }
+        };
+
+
+        Session session = Session.getInstance(mailProps, authenticator);
+
+        MimeMessage message = new MimeMessage(session);
+        message.setFrom(new InternetAddress(senderEmail));
+        message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail));
+        message.setSubject("您的数学学习软件验证码", "UTF-8");
+
+
+        String content = "<h3>欢迎使用数学学习软件！</h3>" +
+                "<p>您的注册验证码是：<b style='color: #007bff; font-size: 18px;'>" + code + "</b></p>" +
+                "<p>该验证码5分钟内有效，请勿泄露给他人。</p>";
+        message.setContent(content, "text/html; charset=UTF-8");
+
+
+        Transport.send(message);
+        System.out.println("验证码邮件已成功发送至 " + recipientEmail);
+    }
+}

src/service/ExamManager.java

@@ -0,0 +1,169 @@
+package service;
+
+import model.Question;
+import model.User;
+import model.UserType;
+import service.generator.*;
+
+import java.io.PrintWriter;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.text.SimpleDateFormat;
+import java.util.*;
+
+public class ExamManager {
+    private final Map<UserType, QuestionGenerator> generators = new HashMap<>();
+
+    public ExamManager() {
+        generators.put(UserType.PRIMARY, new PrimaryQuestionGenerator());
+        generators.put(UserType.JUNIOR, new JuniorQuestionGenerator());
+        generators.put(UserType.SENIOR, new SeniorQuestionGenerator());
+    }
+
+    public List<Question> generateExam(User user, UserType userType, int count) {
+        QuestionGenerator generator = generators.get(userType);
+        if (generator == null) throw new IllegalArgumentException("不支持的用户类型");
+
+        List<Question> questions = new ArrayList<>();
+        Set<String> generatedTexts = new HashSet<>();
+        int maxAttempts = count * 20;
+        int attempts = 0;
+
+        while (questions.size() < count && attempts < maxAttempts) {
+            String qText = generator.generateQuestion();
+            if (generatedTexts.contains(qText)) {
+                attempts++;
+                continue;
+            }
+            try {
+                double answer = ExpressionEvaluator.evaluate(qText);
+                if (Double.isInfinite(answer) || Double.isNaN(answer)) continue;
+
+                List<String> options = generateOptions(answer); // 调用已优化的方法
+                int correctIndex = options.indexOf(formatAnswer(answer));
+
+                questions.add(new Question(qText, options, correctIndex));
+                generatedTexts.add(qText);
+            } catch (Exception e) {
+
+            } finally {
+                attempts++;
+            }
+        }
+
+        if (!questions.isEmpty()) {
+            saveExamToFile(user, questions);
+        }
+
+        return questions;
+    }
+
+
+    private List<String> generateOptions(double correctAnswer) {
+        Set<String> options = new LinkedHashSet<>();
+        options.add(formatAnswer(correctAnswer));
+        Random rand = new Random();
+
+        // 判断答案是否为整数
+        boolean isIntegerAnswer = Math.abs(correctAnswer - Math.round(correctAnswer)) < 1e-9;
+
+        while (options.size() < 4) {
+            String distractorStr;
+            if (isIntegerAnswer) {
+
+                int intAnswer = (int) Math.round(correctAnswer);
+                int distractor;
+                int type = rand.nextInt(3); // 三种整数干扰策略
+
+                switch(type) {
+                    case 0: // 策略一：在答案附近加减一个较小的随机数
+                        distractor = intAnswer + (rand.nextInt(8) + 1) * (rand.nextBoolean() ? 1 : -1);
+                        break;
+                    case 1: // 策略二：模拟看错位的错误（加减10）
+                        distractor = intAnswer + (rand.nextBoolean() ? 10 : -10);
+                        break;
+                    default: // 策略三：颠倒个位和十位（如果答案是两位数）
+                        if (intAnswer >= 10 && intAnswer <= 99) {
+                            distractor = (intAnswer % 10) * 10 + (intAnswer / 10);
+                        } else {
+                            // 如果不是两位数，则使用策略一
+                            distractor = intAnswer + (rand.nextInt(8) + 1) * (rand.nextBoolean() ? 1 : -1);
+                        }
+                        break;
+                }
+
+                // 确保干扰项不等于正确答案
+                if (distractor == intAnswer) {
+                    distractor++;
+                }
+                distractorStr = String.valueOf(distractor);
+
+            } else {
+                double distractor;
+                if (rand.nextBoolean()) { // 乘法干扰
+                    distractor = correctAnswer * (rand.nextDouble() * 1.5 + 0.5);
+                } else { // 临近值干扰
+                    distractor = correctAnswer + (rand.nextDouble() - 0.5) * Math.max(1, Math.abs(correctAnswer * 0.2));
+                }
+                distractorStr = formatAnswer(distractor);
+            }
+
+            // 确保选项不重复
+            if (!options.contains(distractorStr)) {
+                options.add(distractorStr);
+            }
+        }
+
+        List<String> shuffledOptions = new ArrayList<>(options);
+        Collections.shuffle(shuffledOptions);
+        return shuffledOptions;
+    }
+
+    private void saveExamToFile(User user, List<Question> questions) {
+        try {
+            Path userExamDir = Paths.get("exams", user.getEmail());
+            Files.createDirectories(userExamDir);
+
+            String timestamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
+            Path examFile = userExamDir.resolve("exam_" + timestamp + ".txt");
+
+            try (PrintWriter writer = new PrintWriter(Files.newBufferedWriter(examFile, StandardCharsets.UTF_8))) {
+                writer.println("用户: " + user.getEmail());
+                writer.println("时间: " + new Date());
+                writer.println("题目类型: " + user.getUserType().getDisplayName());
+                writer.println("题目数量: " + questions.size());
+                writer.println("========================================");
+                writer.println();
+
+                for (int i = 0; i < questions.size(); i++) {
+                    Question q = questions.get(i);
+                    writer.println((i + 1) + ". " + q.getQuestionText());
+
+                    List<String> options = q.getOptions();
+                    char optionLabel = 'A';
+                    for (int j = 0; j < options.size(); j++) {
+                        writer.println("   " + optionLabel + ". " + options.get(j));
+                        optionLabel++;
+                    }
+
+                    writer.println("   正确答案: " + (char)('A' + q.getCorrectOptionIndex()));
+                    writer.println();
+                }
+            }
+            System.out.println("试卷已成功保存至: " + examFile.toAbsolutePath());
+        } catch (IOException e) {
+            System.err.println("保存试卷文件时出错: " + e.getMessage());
+        }
+    }
+
+    private String formatAnswer(double number) {
+        if (Math.abs(number - Math.round(number)) < 1e-9) {
+            return String.valueOf((long) Math.round(number));
+        } else {
+            return String.format("%.2f", number);
+        }
+    }
+}

src/service/ExpressionEvaluator.java

@@ -0,0 +1,120 @@
+package service;
+
+import java.util.Stack;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+
+public class ExpressionEvaluator {
+
+
+
+    public static double evaluate(String expression) {
+        // 1. 预处理，将特殊运算（开方、平方、三角函数）直接计算并替换为数值
+        String processedExpr = preprocessSpecialOperations(expression);
+
+        // 2. 使用双栈算法计算最终的四则运算表达式
+        return calculateStandardExpression(processedExpr);
+    }
+
+
+    private static String preprocessSpecialOperations(String expr) {
+        // 替换中文运算符
+        expr = expr.replace('×', '*').replace('÷', '/');
+
+        // 匹配并计算三角函数，例如 sin(30°)
+        Pattern trigPattern = Pattern.compile("(sin|cos|tan)\\((\\d+)°\\)");
+        Matcher trigMatcher = trigPattern.matcher(expr);
+        while (trigMatcher.find()) {
+            String func = trigMatcher.group(1);
+            double angle = Double.parseDouble(trigMatcher.group(2));
+            double value = 0.0;
+            switch (func) {
+                case "sin": value = Math.sin(Math.toRadians(angle)); break;
+                case "cos": value = Math.cos(Math.toRadians(angle)); break;
+                case "tan": value = Math.tan(Math.toRadians(angle)); break;
+            }
+            expr = trigMatcher.replaceFirst(String.format("%.4f", value));
+            trigMatcher = trigPattern.matcher(expr);
+        }
+
+        // 匹配并计算平方，例如 5^2
+        Pattern squarePattern = Pattern.compile("(\\d+)\\^2");
+        Matcher squareMatcher = squarePattern.matcher(expr);
+        while (squareMatcher.find()) {
+            double base = Double.parseDouble(squareMatcher.group(1));
+            expr = squareMatcher.replaceFirst(String.valueOf(base * base));
+            squareMatcher = squarePattern.matcher(expr);
+        }
+
+        // 匹配并计算开方，例如 √(16)
+        Pattern sqrtPattern = Pattern.compile("√\\((\\d+)\\)");
+        Matcher sqrtMatcher = sqrtPattern.matcher(expr);
+        while (sqrtMatcher.find()) {
+            double num = Double.parseDouble(sqrtMatcher.group(1));
+            expr = sqrtMatcher.replaceFirst(String.valueOf(Math.sqrt(num)));
+            sqrtMatcher = sqrtPattern.matcher(expr);
+        }
+
+        return expr;
+    }
+
+
+    private static double calculateStandardExpression(String expression) {
+        Stack<Double> values = new Stack<>();
+        Stack<Character> ops = new Stack<>();
+        char[] tokens = expression.toCharArray();
+
+        for (int i = 0; i < tokens.length; i++) {
+            if (tokens[i] == ' ') continue;
+
+            if ((tokens[i] >= '0' && tokens[i] <= '9') || tokens[i] == '.') {
+                StringBuilder sbuf = new StringBuilder();
+                while (i < tokens.length && ((tokens[i] >= '0' && tokens[i] <= '9') || tokens[i] == '.')) {
+                    sbuf.append(tokens[i++]);
+                }
+                i--;
+                values.push(Double.parseDouble(sbuf.toString()));
+            } else if (tokens[i] == '(') {
+                ops.push(tokens[i]);
+            } else if (tokens[i] == ')') {
+                while (ops.peek() != '(') {
+                    values.push(applyOp(ops.pop(), values.pop(), values.pop()));
+                }
+                ops.pop();
+            } else if (isOperator(tokens[i])) {
+                while (!ops.empty() && hasPrecedence(tokens[i], ops.peek())) {
+                    values.push(applyOp(ops.pop(), values.pop(), values.pop()));
+                }
+                ops.push(tokens[i]);
+            }
+        }
+
+        while (!ops.empty()) {
+            values.push(applyOp(ops.pop(), values.pop(), values.pop()));
+        }
+
+        return values.pop();
+    }
+
+    private static boolean isOperator(char c) {
+        return c == '+' || c == '-' || c == '*' || c == '/';
+    }
+
+    private static boolean hasPrecedence(char op1, char op2) {
+        if (op2 == '(' || op2 == ')') return false;
+        return (op1 != '*' && op1 != '/') || (op2 != '+' && op2 != '-');
+    }
+
+    private static double applyOp(char op, double b, double a) {
+        switch (op) {
+            case '+': return a + b;
+            case '-': return a - b;
+            case '*': return a * b;
+            case '/':
+                if (b == 0) throw new UnsupportedOperationException("不能除以零");
+                return a / b;
+        }
+        return 0;
+    }
+}

src/service/UserManager.java

@@ -0,0 +1,97 @@
+package service;
+
+import model.User;
+import model.UserType;
+import java.io.*;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.*;
+import java.util.*;
+
+
+
+public class UserManager {
+    private final Path usersFile = Paths.get("data", "users.txt");
+    private final Map<String, User> usersByEmail = new HashMap<>(); // 使用邮箱作为主键
+
+    public UserManager() {
+        try {
+            Files.createDirectories(usersFile.getParent());
+            if (!Files.exists(usersFile)) Files.createFile(usersFile);
+            loadUsers();
+        } catch (IOException e) {
+            System.err.println("初始化用户管理器时出错: " + e.getMessage());
+        }
+    }
+
+    private void loadUsers() throws IOException {
+        List<String> lines = Files.readAllLines(usersFile, StandardCharsets.UTF_8);
+        for (String line : lines) {
+            User user = User.fromString(line);
+            if (user != null) usersByEmail.put(user.getEmail(), user);
+        }
+    }
+
+    private void saveUsers() {
+        try (BufferedWriter writer = Files.newBufferedWriter(usersFile, StandardCharsets.UTF_8)) {
+            for (User user : usersByEmail.values()) writer.write(user.toString() + "\n");
+        } catch (IOException e) {
+            System.err.println("保存用户时出错: " + e.getMessage());
+        }
+    }
+
+
+
+    public User authenticate(String identifier, String password) {
+        String hashedInput = hashPassword(password);
+
+        // 策略一：尝试将 identifier 作为邮箱进行快速查找
+        User userByEmail = usersByEmail.get(identifier);
+        if (userByEmail != null && userByEmail.getHashedPassword().equals(hashedInput)) {
+            return userByEmail; // 邮箱匹配成功
+        }
+
+        // 策略二：如果邮箱查找失败，则遍历所有用户，尝试匹配用户名
+        for (User user : usersByEmail.values()) {
+            if (user.getUsername() != null && user.getUsername().equals(identifier)) {
+                if (user.getHashedPassword().equals(hashedInput)) {
+                    return user; // 用户名匹配成功
+                }
+                break; // 用户名是唯一的，找到后无需继续遍历
+            }
+        }
+
+        return null; // 认证失败
+    }
+
+    public boolean emailExists(String email) {
+        return usersByEmail.containsKey(email);
+    }
+
+    public boolean usernameExists(String username) {
+        if (username == null || username.trim().isEmpty()) return false;
+        for (User user : usersByEmail.values()) {
+            if (username.equals(user.getUsername())) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void registerUser(String email, String username, String password, UserType type) {
+        User newUser = new User(email, username, "", type);
+        newUser.setHashedPassword(password);
+        usersByEmail.put(email, newUser);
+        saveUsers();
+    }
+
+    public void updateUser(User user) {
+        if (usersByEmail.containsKey(user.getEmail())) {
+            usersByEmail.put(user.getEmail(), user);
+            saveUsers();
+        }
+    }
+
+    private String hashPassword(String password) {
+        return Integer.toString(password.hashCode());
+    }
+}

src/service/ValidationService.java

@@ -0,0 +1,25 @@
+package service;
+
+
+public class ValidationService {
+    public static boolean isValidEmail(String email) {
+        if (email == null || email.trim().isEmpty()) {
+            return false;
+        }
+        String emailRegex = "^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$";
+        return email.matches(emailRegex);
+    }
+
+    public static boolean isPasswordStrong(String password) {
+        if (password == null || password.length() < 6 || password.length() > 10) {
+            return false;
+        }
+        boolean hasUpperCase = password.matches(".*[A-Z].*");
+        boolean hasLowerCase = password.matches(".*[a-z].*");
+        boolean hasDigit = password.matches(".*[0-9].*");
+
+        return hasUpperCase && hasLowerCase && hasDigit;
+    }
+}
+
+

src/service/generator/AbstractQuestionGenerator.java

@@ -0,0 +1,61 @@
+package service.generator;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Random;
+
+public abstract class AbstractQuestionGenerator implements QuestionGenerator {
+    protected final Random rand = new Random();
+    private static final char[] OPS = {'+', '-', '×', '÷'};
+
+    protected String buildComplexExpression(List<String> operands) {
+        int numOperands = operands.size();
+        if (numOperands < 2) return operands.get(0); // 如果只有一个操作数，直接返回
+
+        List<Character> operators = new ArrayList<>();
+        for (int i = 0; i < numOperands - 1; i++) {
+            operators.add(OPS[rand.nextInt(OPS.length)]);
+        }
+
+        int parensType = rand.nextInt(5); // 增加不加括号的概率
+
+        switch (parensType) {
+            case 1: // 单括号 (a op b) op c ...
+                if (numOperands >= 3) {
+                    Collections.swap(operands, 0, rand.nextInt(numOperands));
+                    Collections.swap(operands, 1, rand.nextInt(numOperands));
+                    return String.format("(%s %c %s) %c %s", operands.get(0), operators.get(0), operands.get(1), operators.get(1), buildRest(operands, operators, 2));
+                }
+                break;
+            case 2: // a op (b op c) op d ...
+                if (numOperands >= 3) {
+                    return String.format("%s %c (%s %c %s)", operands.get(0), operators.get(0), operands.get(1), operators.get(1), buildRest(operands, operators, 2));
+                }
+                break;
+            case 3: // 双重括号 ((a op b) op c) op d ...
+                if (numOperands >= 4) {
+                    return String.format("((%s %c %s) %c %s) %c %s", operands.get(0), operators.get(0), operands.get(1), operators.get(1), operands.get(2), operators.get(2), buildRest(operands, operators, 3));
+                }
+                break;
+            case 4: // 双重括号 a op (b op (c op d)) ...
+                if (numOperands >= 4) {
+                    return String.format("%s %c (%s %c (%s %c %s))", operands.get(0), operators.get(0), operands.get(1), operators.get(1), operands.get(2), operators.get(2), buildRest(operands, operators, 3));
+                }
+                break;
+        }
+
+        // 默认情况：无括号或无法应用括号
+        return buildRest(operands, operators, 0);
+    }
+
+    private String buildRest(List<String> operands, List<Character> operators, int startIndex) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(operands.get(startIndex));
+        for (int i = startIndex; i < operators.size(); i++) {
+            sb.append(" ").append(operators.get(i)).append(" ");
+            sb.append(operands.get(i + 1));
+        }
+        return sb.toString();
+    }
+}

src/service/generator/JuniorQuestionGenerator.java

@@ -0,0 +1,49 @@
+package service.generator;
+
+import java.util.Random;
+public class JuniorQuestionGenerator implements QuestionGenerator {
+    private final Random rand = new Random();
+
+    @Override
+    public String generateQuestion() {
+        int numOperands = rand.nextInt(4) + 2; // 2-5个操作数
+        String[] operands = new String[numOperands];
+
+        // 先填充普通数字
+        for (int i = 0; i < numOperands; i++) {
+            operands[i] = String.valueOf(num(15));
+        }
+
+        // 随机替换一个为特殊运算
+        int specialIndex = rand.nextInt(numOperands);
+        operands[specialIndex] = specialOp();
+
+        // 根据操作数数量选择模板
+        switch (numOperands) {
+            case 2:
+                return String.format("%s %c %s", operands[0], op(), operands[1]);
+            case 3:
+                return String.format("(%s %c %s) %c %s", operands[0], opLow(), operands[1], opHigh(), operands[2]);
+            case 4:
+                return String.format("(%s %c %s) %c (%s %c %s)", operands[0], opHigh(), operands[1], opLow(), operands[2], opLow(), operands[3]);
+            case 5:
+            default:
+                return String.format("((%s %c %s) %c %s) %c (%s %c %s)", operands[0], opLow(), operands[1], opHigh(), operands[2], opLow(), operands[3], opLow(), operands[4]);
+        }
+    }
+
+    // --- 辅助方法 ---
+    private int num(int bound) { return rand.nextInt(bound) + 1; }
+    private char op() { return "+-×".charAt(rand.nextInt(3)); }
+    private char opLow() { return "+-".charAt(rand.nextInt(2)); }
+    private char opHigh() { return '×'; }
+
+    private String specialOp() {
+        if (rand.nextBoolean()) {
+            return (rand.nextInt(9) + 2) + "^2"; // 2^2 to 10^2
+        } else {
+            int base = rand.nextInt(10) + 1;
+            return "√(" + (base * base) + ")";
+        }
+    }
+}

src/service/generator/PrimaryQuestionGenerator.java

@@ -0,0 +1,69 @@
+package service.generator;
+
+import java.util.Random;
+
+public class PrimaryQuestionGenerator implements QuestionGenerator {
+    private final Random rand = new Random();
+
+    @Override
+    public String generateQuestion() {
+        int numOperands = rand.nextInt(4) + 2; // 随机生成2-5个操作数
+
+        switch (numOperands) {
+            case 2:
+                return simpleExpression(num(50), op(), num(50));
+            case 3:
+                return generateThreeOperandExpression();
+            case 4:
+                return generateFourOperandExpression();
+            case 5:
+            default:
+                return generateFiveOperandExpression();
+        }
+    }
+
+    private String generateThreeOperandExpression() {
+        if (rand.nextBoolean()) {
+            // 模板: (a + b) * c
+            return String.format("(%d %c %d) %c %d", num(20), opLow(), num(20), opHigh(), num(10));
+        } else {
+            // 模板: a * (b - c)
+
+            int b = num(29) + 1; // b 的范围是 2 到 30
+            int c = num(b - 1);  // c 的范围是 1 到 b-1，确保 c < b
+            return String.format("%d %c (%d %c %d)", num(10), opHigh(), b, opLow(), c);
+        }
+    }
+
+    private String generateFourOperandExpression() {
+        if (rand.nextBoolean()) {
+            // 模板: ((a + b) * c) - d
+            return String.format("((%d %c %d) %c %d) %c %d", num(10), opLow(), num(10), opHigh(), num(5), opLow(), num(20));
+        } else {
+            // 模板: a * (b - (c + d))
+            return String.format("%d %c (%d %c (%d %c %d))", num(5), opHigh(), num(50), opLow(), num(10), opLow(), num(10));
+        }
+    }
+
+    private String generateFiveOperandExpression() {
+        // 模板: (a * b) + (c - d) * e
+        int c = num(29) + 1; // c 的范围是 2 到 30
+        int d = num(c - 1);  // d 的范围是 1 到 c-1，确保 d < c
+        return String.format("(%d %c %d) %c (%d %c %d) %c %d", num(10), opHigh(), num(10), opLow(), c, opLow(), d, opHigh(), num(5));
+    }
+
+    // --- 辅助方法 ---
+    private int num(int bound) {
+        // 健壮性检查，防止外部调用传入无效的bound
+        if (bound <= 0) return 1;
+        return rand.nextInt(bound) + 1;
+    }
+    private char op() { return "+-×÷".charAt(rand.nextInt(4)); }
+    private char opLow() { return "+-".charAt(rand.nextInt(2)); } // 低优先级
+    private char opHigh() { return "×÷".charAt(rand.nextInt(2)); } // 高优先级
+    private String simpleExpression(int a, char op, int b) {
+        if (op == '÷') a = b * num(10);
+        if (op == '-') a = Math.max(a, b + 1);
+        return String.format("%d %c %d", a, op, b);
+    }
+}

src/service/generator/QuestionGenerator.java

@@ -0,0 +1,5 @@
+package service.generator;
+
+public interface QuestionGenerator {
+    String generateQuestion();
+}

src/service/generator/SeniorQuestionGenerator.java

@@ -0,0 +1,51 @@
+package service.generator;
+
+import java.util.Random;
+
+public class SeniorQuestionGenerator implements QuestionGenerator {
+    private final Random rand = new Random();
+    private static final String[] TRIG_FUNCS = {"sin", "cos", "tan"};
+    private static final int[] COMMON_ANGLES = {0, 30, 45, 60, 90,135,180};
+    private static final int[] TAN_SAFE_ANGLES = {0, 30, 45, 60,135};
+
+    @Override
+    public String generateQuestion() {
+        int numOperands = rand.nextInt(3) + 2; // 2-4个操作数以控制复杂度
+        String[] operands = new String[numOperands];
+
+        for (int i = 0; i < numOperands; i++) {
+            operands[i] = String.valueOf(num(10));
+        }
+
+        int specialIndex = rand.nextInt(numOperands);
+        operands[specialIndex] = specialOp();
+
+        switch (numOperands) {
+            case 2:
+                return String.format("%s %c %s", operands[0], op(), operands[1]);
+            case 3:
+                return String.format("(%s %c %s) %c %s", operands[0], opLow(), operands[1], opHigh(), operands[2]);
+            case 4:
+            default:
+                return String.format("%s %c (%s %c (%s %c %s))", operands[0], opHigh(), operands[1], opLow(), operands[2], opLow(), operands[3]);
+        }
+    }
+
+    // --- 辅助方法 ---
+    private int num(int bound) { return rand.nextInt(bound) + 1; }
+    private char op() { return "+-×".charAt(rand.nextInt(3)); }
+    private char opLow() { return "+-".charAt(rand.nextInt(2)); }
+    private char opHigh() { return '×'; }
+
+    private String specialOp() {
+        String func = TRIG_FUNCS[rand.nextInt(TRIG_FUNCS.length)];
+        int angle;
+
+        if (func.equals("tan")) {
+            angle = TAN_SAFE_ANGLES[rand.nextInt(TAN_SAFE_ANGLES.length)];
+        } else {
+            angle = COMMON_ANGLES[rand.nextInt(COMMON_ANGLES.length)];
+        }
+        return String.format("%s(%d°)", func, angle);
+    }
+}

src/view/ExamView.java

@@ -1,140 +1,140 @@
-package view;
-
-import model.Question;
-import javax.swing.*;
-import javax.swing.border.EmptyBorder;
-import javax.swing.text.SimpleAttributeSet;
-import javax.swing.text.StyleConstants;
-import javax.swing.text.StyledDocument;
-import java.awt.*;
-import java.util.List;
-
-
-public class ExamView extends JPanel {
-    private final JLabel progressLabel = new JLabel(" ", SwingConstants.CENTER);
-    private final JProgressBar progressBar = new JProgressBar();
-    private final JTextPane questionPane = new JTextPane();
-    private final JRadioButton[] optionButtons = new JRadioButton[4];
-    private final ButtonGroup optionsGroup = new ButtonGroup();
-
-    private final JButton prevButton = new JButton("上一题");
-    private final JButton nextButton = new JButton("下一题");
-    private final JButton finishButton = new JButton("交卷并评分");
-
-    public ExamView() {
-        setLayout(new BorderLayout(20, 20));
-        setBorder(new EmptyBorder(20, 40, 40, 40));
-
-        // --- 顶部进度区域 ---
-        JPanel topPanel = new JPanel(new BorderLayout(0, 10));
-        progressLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));
-        topPanel.add(progressLabel, BorderLayout.NORTH);
-
-        progressBar.setPreferredSize(new Dimension(1, 15));
-        topPanel.add(progressBar, BorderLayout.CENTER);
-        add(topPanel, BorderLayout.NORTH);
-
-        // --- 中间题目区域 ---
-        questionPane.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 36));
-        questionPane.setEditable(false);
-        questionPane.setFocusable(false);
-        questionPane.setOpaque(false);
-        StyledDocument doc = questionPane.getStyledDocument();
-        SimpleAttributeSet center = new SimpleAttributeSet();
-        StyleConstants.setAlignment(center, StyleConstants.ALIGN_CENTER);
-        doc.setParagraphAttributes(0, doc.getLength(), center, false);
-
-        JPanel questionWrapper = new JPanel(new BorderLayout());
-        questionWrapper.setOpaque(false);
-        questionWrapper.add(questionPane, BorderLayout.CENTER);
-        add(questionWrapper, BorderLayout.CENTER);
-
-        // --- 底部选项和导航 ---
-        JPanel southPanel = new JPanel(new BorderLayout(20, 30));
-
-        // --- 选项面板 ---
-        JPanel optionsPanel = new JPanel(new GridBagLayout());
-        optionsPanel.setOpaque(false);
-        GridBagConstraints gbcOpt = new GridBagConstraints();
-        gbcOpt.insets = new Insets(15, 80, 15, 80); // 调整选项的内外边距
-        gbcOpt.anchor = GridBagConstraints.WEST;
-
-        for (int i = 0; i < 4; i++) {
-            optionButtons[i] = new JRadioButton();
-            optionButtons[i].setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 20));
-            optionButtons[i].setOpaque(false);
-            optionsGroup.add(optionButtons[i]);
-        }
-
-
-        gbcOpt.gridx = 0; gbcOpt.gridy = 0; optionsPanel.add(optionButtons[0], gbcOpt); // 位置 A
-        gbcOpt.gridx = 1; gbcOpt.gridy = 0; optionsPanel.add(optionButtons[1], gbcOpt); // 位置 B
-        gbcOpt.gridx = 0; gbcOpt.gridy = 1; optionsPanel.add(optionButtons[2], gbcOpt); // 位置 C
-        gbcOpt.gridx = 1; gbcOpt.gridy = 1; optionsPanel.add(optionButtons[3], gbcOpt); // 位置 D
-
-        JPanel optionsWrapper = new JPanel(new GridBagLayout());
-        optionsWrapper.setOpaque(false);
-        optionsWrapper.add(optionsPanel);
-        southPanel.add(optionsWrapper, BorderLayout.CENTER);
-
-        // --- 导航按钮面板 ---
-        JPanel navigationPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 30, 0));
-        prevButton.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        nextButton.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        finishButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
-        finishButton.putClientProperty("JButton.buttonType", "roundRect");
-
-        navigationPanel.add(prevButton);
-        navigationPanel.add(finishButton);
-        navigationPanel.add(nextButton);
-        southPanel.add(navigationPanel, BorderLayout.SOUTH);
-
-        add(southPanel, BorderLayout.SOUTH);
-    }
-
-    public void displayQuestion(Question q, int qNum, int total, int savedAnswerIndex) {
-        progressLabel.setText(String.format("第 %d 题 / 共 %d 题", qNum, total));
-        progressBar.setValue(qNum);
-        questionPane.setText(q.getQuestionText());
-
-        StyledDocument doc = questionPane.getStyledDocument();
-        SimpleAttributeSet center = new SimpleAttributeSet();
-        StyleConstants.setAlignment(center, StyleConstants.ALIGN_CENTER);
-        doc.setParagraphAttributes(0, doc.getLength(), center, false);
-
-        optionsGroup.clearSelection();
-        List<String> options = q.getOptions();
-
-        char optionLabel = 'A';
-        for (int i = 0; i < 4; i++) {
-            optionButtons[i].setText(optionLabel + ". " + options.get(i));
-            optionLabel++;
-        }
-
-        if (savedAnswerIndex != -1) {
-            optionButtons[savedAnswerIndex].setSelected(true);
-        }
-    }
-
-    public void setupForExam(int totalQuestions) {
-        progressBar.setMinimum(1);
-        progressBar.setMaximum(totalQuestions);
-    }
-
-    public void updateNavigationButtons(int qIndex, int total) {
-        prevButton.setEnabled(qIndex > 0);
-        nextButton.setEnabled(qIndex < total - 1);
-        nextButton.setText(qIndex == total - 2 ? "最后一题" : "下一题");
-    }
-
-    public int getSelectedIndex() {
-        for (int i = 0; i < 4; i++) {
-            if (optionButtons[i].isSelected()) { return i; }
-        }
-        return -1;
-    }
-
-    public JButton getPrevButton() { return prevButton; }
-    public JButton getNextButton() { return nextButton; }
-    public JButton getFinishButton() { return finishButton; }
+package view;
+
+import model.Question;
+import javax.swing.*;
+import javax.swing.border.EmptyBorder;
+import javax.swing.text.SimpleAttributeSet;
+import javax.swing.text.StyleConstants;
+import javax.swing.text.StyledDocument;
+import java.awt.*;
+import java.util.List;
+
+
+public class ExamView extends JPanel {
+    private final JLabel progressLabel = new JLabel(" ", SwingConstants.CENTER);
+    private final JProgressBar progressBar = new JProgressBar();
+    private final JTextPane questionPane = new JTextPane();
+    private final JRadioButton[] optionButtons = new JRadioButton[4];
+    private final ButtonGroup optionsGroup = new ButtonGroup();
+
+    private final JButton prevButton = new JButton("上一题");
+    private final JButton nextButton = new JButton("下一题");
+    private final JButton finishButton = new JButton("交卷并评分");
+
+    public ExamView() {
+        setLayout(new BorderLayout(20, 20));
+        setBorder(new EmptyBorder(20, 40, 40, 40));
+
+        // --- 顶部进度区域 ---
+        JPanel topPanel = new JPanel(new BorderLayout(0, 10));
+        progressLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));
+        topPanel.add(progressLabel, BorderLayout.NORTH);
+
+        progressBar.setPreferredSize(new Dimension(1, 15));
+        topPanel.add(progressBar, BorderLayout.CENTER);
+        add(topPanel, BorderLayout.NORTH);
+
+        // --- 中间题目区域 ---
+        questionPane.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 36));
+        questionPane.setEditable(false);
+        questionPane.setFocusable(false);
+        questionPane.setOpaque(false);
+        StyledDocument doc = questionPane.getStyledDocument();
+        SimpleAttributeSet center = new SimpleAttributeSet();
+        StyleConstants.setAlignment(center, StyleConstants.ALIGN_CENTER);
+        doc.setParagraphAttributes(0, doc.getLength(), center, false);
+
+        JPanel questionWrapper = new JPanel(new BorderLayout());
+        questionWrapper.setOpaque(false);
+        questionWrapper.add(questionPane, BorderLayout.CENTER);
+        add(questionWrapper, BorderLayout.CENTER);
+
+        // --- 底部选项和导航 ---
+        JPanel southPanel = new JPanel(new BorderLayout(20, 30));
+
+        // --- 选项面板 ---
+        JPanel optionsPanel = new JPanel(new GridBagLayout());
+        optionsPanel.setOpaque(false);
+        GridBagConstraints gbcOpt = new GridBagConstraints();
+        gbcOpt.insets = new Insets(15, 80, 15, 80); // 调整选项的内外边距
+        gbcOpt.anchor = GridBagConstraints.WEST;
+
+        for (int i = 0; i < 4; i++) {
+            optionButtons[i] = new JRadioButton();
+            optionButtons[i].setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 20));
+            optionButtons[i].setOpaque(false);
+            optionsGroup.add(optionButtons[i]);
+        }
+
+
+        gbcOpt.gridx = 0; gbcOpt.gridy = 0; optionsPanel.add(optionButtons[0], gbcOpt); // 位置 A
+        gbcOpt.gridx = 1; gbcOpt.gridy = 0; optionsPanel.add(optionButtons[1], gbcOpt); // 位置 B
+        gbcOpt.gridx = 0; gbcOpt.gridy = 1; optionsPanel.add(optionButtons[2], gbcOpt); // 位置 C
+        gbcOpt.gridx = 1; gbcOpt.gridy = 1; optionsPanel.add(optionButtons[3], gbcOpt); // 位置 D
+
+        JPanel optionsWrapper = new JPanel(new GridBagLayout());
+        optionsWrapper.setOpaque(false);
+        optionsWrapper.add(optionsPanel);
+        southPanel.add(optionsWrapper, BorderLayout.CENTER);
+
+        // --- 导航按钮面板 ---
+        JPanel navigationPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 30, 0));
+        prevButton.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        nextButton.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        finishButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
+        finishButton.putClientProperty("JButton.buttonType", "roundRect");
+
+        navigationPanel.add(prevButton);
+        navigationPanel.add(finishButton);
+        navigationPanel.add(nextButton);
+        southPanel.add(navigationPanel, BorderLayout.SOUTH);
+
+        add(southPanel, BorderLayout.SOUTH);
+    }
+
+    public void displayQuestion(Question q, int qNum, int total, int savedAnswerIndex) {
+        progressLabel.setText(String.format("第 %d 题 / 共 %d 题", qNum, total));
+        progressBar.setValue(qNum);
+        questionPane.setText(q.getQuestionText());
+
+        StyledDocument doc = questionPane.getStyledDocument();
+        SimpleAttributeSet center = new SimpleAttributeSet();
+        StyleConstants.setAlignment(center, StyleConstants.ALIGN_CENTER);
+        doc.setParagraphAttributes(0, doc.getLength(), center, false);
+
+        optionsGroup.clearSelection();
+        List<String> options = q.getOptions();
+
+        char optionLabel = 'A';
+        for (int i = 0; i < 4; i++) {
+            optionButtons[i].setText(optionLabel + ". " + options.get(i));
+            optionLabel++;
+        }
+
+        if (savedAnswerIndex != -1) {
+            optionButtons[savedAnswerIndex].setSelected(true);
+        }
+    }
+
+    public void setupForExam(int totalQuestions) {
+        progressBar.setMinimum(1);
+        progressBar.setMaximum(totalQuestions);
+    }
+
+    public void updateNavigationButtons(int qIndex, int total) {
+        prevButton.setEnabled(qIndex > 0);
+        nextButton.setEnabled(qIndex < total - 1);
+        nextButton.setText(qIndex == total - 2 ? "最后一题" : "下一题");
+    }
+
+    public int getSelectedIndex() {
+        for (int i = 0; i < 4; i++) {
+            if (optionButtons[i].isSelected()) { return i; }
+        }
+        return -1;
+    }
+
+    public JButton getPrevButton() { return prevButton; }
+    public JButton getNextButton() { return nextButton; }
+    public JButton getFinishButton() { return finishButton; }
 }

src/view/LoginView.java

@@ -1,64 +1,64 @@
-package view;
-
-import javax.swing.*;
-import java.awt.*;
-
-public class LoginView extends JPanel {
-    private final JTextField identifierField = new JTextField(20);
-    private final JPasswordField passwordField = new JPasswordField(20);
-    private final JButton loginButton = new JButton("登 录");
-    private final JButton registerButton = new JButton("还没有账号？立即注册");
-
-    public LoginView() {
-        setLayout(new GridBagLayout());
-
-        JPanel formPanel = new JPanel(new GridBagLayout());
-        formPanel.setBorder(BorderFactory.createEmptyBorder(30, 40, 30, 40));
-        GridBagConstraints gbc = new GridBagConstraints();
-        gbc.insets = new Insets(10, 10, 10, 10);
-        gbc.fill = GridBagConstraints.HORIZONTAL;
-
-        JLabel titleLabel = new JLabel("欢迎回来", SwingConstants.CENTER);
-        titleLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 28));
-        gbc.gridx = 0; gbc.gridy = 0; gbc.gridwidth = 2;
-        formPanel.add(titleLabel, gbc);
-
-        gbc.gridwidth = 1;
-        gbc.gridx = 0; gbc.gridy = 1; addLabel(formPanel, "邮箱 / 用户名:", gbc);
-        gbc.gridx = 1; gbc.gridy = 1; addComponent(formPanel, identifierField, gbc);
-
-        gbc.gridx = 0; gbc.gridy = 2; addLabel(formPanel, "密码:", gbc);
-        gbc.gridx = 1; gbc.gridy = 2; addComponent(formPanel, passwordField, gbc);
-
-        gbc.gridx = 0; gbc.gridy = 3; gbc.gridwidth = 2;
-        loginButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
-        addComponent(formPanel, loginButton, gbc);
-
-        gbc.gridy = 4;
-
-        registerButton.putClientProperty("FlatLaf.style", "buttonType: borderless");
-        addComponent(formPanel, registerButton, gbc);
-
-        add(formPanel);
-    }
-
-    private void addLabel(JPanel panel, String text, GridBagConstraints gbc) {
-        JLabel label = new JLabel(text);
-        label.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        panel.add(label, gbc);
-    }
-
-    private void addComponent(JPanel panel, JComponent comp, GridBagConstraints gbc) {
-        comp.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        panel.add(comp, gbc);
-    }
-
-    public String getIdentifier() { return identifierField.getText().trim(); }
-    public String getPassword() { return new String(passwordField.getPassword()); }
-    public JButton getLoginButton() { return loginButton; }
-    public JButton getRegisterButton() { return registerButton; }
-    public void clearFields() {
-        identifierField.setText("");
-        passwordField.setText("");
-    }
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+
+public class LoginView extends JPanel {
+    private final JTextField identifierField = new JTextField(20);
+    private final JPasswordField passwordField = new JPasswordField(20);
+    private final JButton loginButton = new JButton("登 录");
+    private final JButton registerButton = new JButton("还没有账号？立即注册");
+
+    public LoginView() {
+        setLayout(new GridBagLayout());
+
+        JPanel formPanel = new JPanel(new GridBagLayout());
+        formPanel.setBorder(BorderFactory.createEmptyBorder(30, 40, 30, 40));
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(10, 10, 10, 10);
+        gbc.fill = GridBagConstraints.HORIZONTAL;
+
+        JLabel titleLabel = new JLabel("欢迎回来", SwingConstants.CENTER);
+        titleLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 28));
+        gbc.gridx = 0; gbc.gridy = 0; gbc.gridwidth = 2;
+        formPanel.add(titleLabel, gbc);
+
+        gbc.gridwidth = 1;
+        gbc.gridx = 0; gbc.gridy = 1; addLabel(formPanel, "邮箱 / 用户名:", gbc);
+        gbc.gridx = 1; gbc.gridy = 1; addComponent(formPanel, identifierField, gbc);
+
+        gbc.gridx = 0; gbc.gridy = 2; addLabel(formPanel, "密码:", gbc);
+        gbc.gridx = 1; gbc.gridy = 2; addComponent(formPanel, passwordField, gbc);
+
+        gbc.gridx = 0; gbc.gridy = 3; gbc.gridwidth = 2;
+        loginButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 16));
+        addComponent(formPanel, loginButton, gbc);
+
+        gbc.gridy = 4;
+
+        registerButton.putClientProperty("FlatLaf.style", "buttonType: borderless");
+        addComponent(formPanel, registerButton, gbc);
+
+        add(formPanel);
+    }
+
+    private void addLabel(JPanel panel, String text, GridBagConstraints gbc) {
+        JLabel label = new JLabel(text);
+        label.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        panel.add(label, gbc);
+    }
+
+    private void addComponent(JPanel panel, JComponent comp, GridBagConstraints gbc) {
+        comp.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        panel.add(comp, gbc);
+    }
+
+    public String getIdentifier() { return identifierField.getText().trim(); }
+    public String getPassword() { return new String(passwordField.getPassword()); }
+    public JButton getLoginButton() { return loginButton; }
+    public JButton getRegisterButton() { return registerButton; }
+    public void clearFields() {
+        identifierField.setText("");
+        passwordField.setText("");
+    }
 }

src/view/MainFrame.java

@@ -1,27 +1,27 @@
-package view;
-
-import javax.swing.*;
-import java.awt.*;
-
-public class MainFrame extends JFrame {
-    private final CardLayout cardLayout = new CardLayout();
-    private final JPanel mainPanel = new JPanel(cardLayout);
-
-    public MainFrame() {
-        super("数学学习软件");
-        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-        setSize(800, 600);
-        setLocationRelativeTo(null);
-        setResizable(false);
-        add(mainPanel);
-    }
-
-    public void addPanel(JPanel panel, String name) {
-        mainPanel.add(panel, name);
-    }
-
-    public void showPanel(String name) {
-        cardLayout.show(mainPanel, name);
-        setVisible(true);
-    }
+package view;
+
+import javax.swing.*;
+import java.awt.*;
+
+public class MainFrame extends JFrame {
+    private final CardLayout cardLayout = new CardLayout();
+    private final JPanel mainPanel = new JPanel(cardLayout);
+
+    public MainFrame() {
+        super("数学学习软件");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(800, 600);
+        setLocationRelativeTo(null);
+        setResizable(false);
+        add(mainPanel);
+    }
+
+    public void addPanel(JPanel panel, String name) {
+        mainPanel.add(panel, name);
+    }
+
+    public void showPanel(String name) {
+        cardLayout.show(mainPanel, name);
+        setVisible(true);
+    }
 }

src/view/MainMenuView.java

@@ -1,72 +1,72 @@
-package view;
-
-import model.UserType;
-import javax.swing.*;
-import java.awt.*;
-
-public class MainMenuView extends JPanel {
-    private final JLabel welcomeLabel = new JLabel("", SwingConstants.CENTER);
-    private final JComboBox<String> typeComboBox = new JComboBox<>();
-    private final JSpinner countSpinner = new JSpinner(new SpinnerNumberModel(10, 10, 30, 1));
-    private final JButton startExamButton = new JButton("开始答题");
-    private final JButton changePasswordButton = new JButton("修改密码");
-    private final JButton logoutButton = new JButton("退出登录");
-
-    public MainMenuView() {
-        setLayout(new BorderLayout(20, 20));
-        setBorder(BorderFactory.createEmptyBorder(40, 40, 40, 40));
-
-        welcomeLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 28));
-        add(welcomeLabel, BorderLayout.NORTH);
-
-        JPanel centerPanel = new JPanel(new GridBagLayout());
-        GridBagConstraints gbc = new GridBagConstraints();
-        gbc.insets = new Insets(15, 10, 15, 10);
-
-        gbc.gridx = 0; gbc.gridy = 0; addLabel(centerPanel, "选择题目难度:", gbc);
-        gbc.gridx = 1; gbc.gridy = 0; addComponent(centerPanel, typeComboBox, gbc);
-
-        gbc.gridx = 0; gbc.gridy = 1; addLabel(centerPanel, "选择题目数量:", gbc);
-        gbc.gridx = 1; gbc.gridy = 1; addComponent(centerPanel, countSpinner, gbc);
-
-        startExamButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));
-
-        startExamButton.putClientProperty("JButton.buttonType", "roundRect");
-        gbc.gridy = 2; gbc.gridwidth = 2; gbc.insets = new Insets(30, 10, 15, 10);
-        addComponent(centerPanel, startExamButton, gbc);
-        add(centerPanel, BorderLayout.CENTER);
-
-        JPanel southPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT, 20, 0));
-        southPanel.add(changePasswordButton);
-        southPanel.add(logoutButton);
-        add(southPanel, BorderLayout.SOUTH);
-
-        for (UserType type : UserType.values()) {
-            typeComboBox.addItem(type.getDisplayName());
-        }
-    }
-
-    private void addLabel(JPanel panel, String text, GridBagConstraints gbc) {
-        JLabel label = new JLabel(text);
-        label.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        panel.add(label, gbc);
-    }
-
-    private void addComponent(JPanel panel, JComponent comp, GridBagConstraints gbc) {
-        comp.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
-        panel.add(comp, gbc);
-    }
-
-    public void setWelcomeMessage(String message) { welcomeLabel.setText(message); }
-    public UserType getSelectedType() {
-        String displayName = (String) typeComboBox.getSelectedItem();
-        for (UserType type : UserType.values()) {
-            if (type.getDisplayName().equals(displayName)) return type;
-        }
-        return UserType.PRIMARY;
-    }
-    public int getQuestionCount() { return (int) countSpinner.getValue(); }
-    public JButton getStartExamButton() { return startExamButton; }
-    public JButton getChangePasswordButton() { return changePasswordButton; }
-    public JButton getLogoutButton() { return logoutButton; }
+package view;
+
+import model.UserType;
+import javax.swing.*;
+import java.awt.*;
+
+public class MainMenuView extends JPanel {
+    private final JLabel welcomeLabel = new JLabel("", SwingConstants.CENTER);
+    private final JComboBox<String> typeComboBox = new JComboBox<>();
+    private final JSpinner countSpinner = new JSpinner(new SpinnerNumberModel(10, 10, 30, 1));
+    private final JButton startExamButton = new JButton("开始答题");
+    private final JButton changePasswordButton = new JButton("修改密码");
+    private final JButton logoutButton = new JButton("退出登录");
+
+    public MainMenuView() {
+        setLayout(new BorderLayout(20, 20));
+        setBorder(BorderFactory.createEmptyBorder(40, 40, 40, 40));
+
+        welcomeLabel.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 28));
+        add(welcomeLabel, BorderLayout.NORTH);
+
+        JPanel centerPanel = new JPanel(new GridBagLayout());
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(15, 10, 15, 10);
+
+        gbc.gridx = 0; gbc.gridy = 0; addLabel(centerPanel, "选择题目难度:", gbc);
+        gbc.gridx = 1; gbc.gridy = 0; addComponent(centerPanel, typeComboBox, gbc);
+
+        gbc.gridx = 0; gbc.gridy = 1; addLabel(centerPanel, "选择题目数量:", gbc);
+        gbc.gridx = 1; gbc.gridy = 1; addComponent(centerPanel, countSpinner, gbc);
+
+        startExamButton.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));
+
+        startExamButton.putClientProperty("JButton.buttonType", "roundRect");
+        gbc.gridy = 2; gbc.gridwidth = 2; gbc.insets = new Insets(30, 10, 15, 10);
+        addComponent(centerPanel, startExamButton, gbc);
+        add(centerPanel, BorderLayout.CENTER);
+
+        JPanel southPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT, 20, 0));
+        southPanel.add(changePasswordButton);
+        southPanel.add(logoutButton);
+        add(southPanel, BorderLayout.SOUTH);
+
+        for (UserType type : UserType.values()) {
+            typeComboBox.addItem(type.getDisplayName());
+        }
+    }
+
+    private void addLabel(JPanel panel, String text, GridBagConstraints gbc) {
+        JLabel label = new JLabel(text);
+        label.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        panel.add(label, gbc);
+    }
+
+    private void addComponent(JPanel panel, JComponent comp, GridBagConstraints gbc) {
+        comp.setFont(new Font(Font.SANS_SERIF, Font.PLAIN, 16));
+        panel.add(comp, gbc);
+    }
+
+    public void setWelcomeMessage(String message) { welcomeLabel.setText(message); }
+    public UserType getSelectedType() {
+        String displayName = (String) typeComboBox.getSelectedItem();
+        for (UserType type : UserType.values()) {
+            if (type.getDisplayName().equals(displayName)) return type;
+        }
+        return UserType.PRIMARY;
+    }
+    public int getQuestionCount() { return (int) countSpinner.getValue(); }
+    public JButton getStartExamButton() { return startExamButton; }
+    public JButton getChangePasswordButton() { return changePasswordButton; }
+    public JButton getLogoutButton() { return logoutButton; }
 }