AI 辅助开发实战：在线考试系统全流程代码解析

这段 SQL 有几个值得注意的细节：完整的字段注释符合企业开发规范；合理的索引设计，尤其是唯一索引有效防止重复考试；包含时间戳字段便于数据追踪；状态字段使用 tinyint 节省存储空间；针对考试业务特点设计了作弊次数等特色字段。

实体类设计：注解驱动的对象映射

基于数据库表结构，AI 自动生成了对应的实体类，采用 Lombok 简化代码：

@Data
@TableName("t_question")
public class Question implements Serializable {
    private static final long serialVersionUID = 1L;

    /**
     * 题目 ID
     */
    @TableId(type = IdType.AUTO)
    private Long id;

    /**
     * 题目类型 ID(1:单选，2:多选，3:判断)
     */
    @TableField("question_type_id")
    @NotNull(message = "题目类型不能为空")
    private Long questionTypeId;

    /**
     * 科目 ID
     */
    @TableField("subject_id")
    @NotNull(message = "科目不能为空")
    private Long subjectId;

    /**
     * 题目内容
     */
    @TableField("content")
    @NotBlank(message = "题目内容不能为空")
    private String content;

    /**
     * 选项 A
     */
    @TableField("option_a")
    private String optionA;

    /**
     * 选项 B
     */
    @TableField("option_b")
    private String optionB;

    /**
     * 选项 C
     */
    @TableField("option_c")
    private String optionC;

    /**
     * 选项 D
     */
    @TableField("option_d")
    private String optionD;

    /**
     * 正确答案
     */
    @TableField("answer")
    @NotBlank(message = "正确答案不能为空")
    private String answer;

    /**
     * 分值
     */
    @TableField("score")
    @Min(value = 1, message = "分值不能小于 1")
    private Integer score;

    /**
     * 难度 (1:易，2:中，3:难)
     */
    @TableField("difficulty")
    @NotNull(message = "难度等级不能为空")
    @Range(min = 1, max = 3, message = "难度等级必须在 1-3 之间")
    private Integer difficulty;

    /**
     * 答案解析
     */
    @TableField("analysis")
    private String analysis;

    /**
     * 创建人
     */
    @TableField("create_by")
    private Long createBy;

    /**
     * 创建时间
     */
    @TableField(value = "create_time", fill = FieldFill.INSERT)
    private LocalDateTime createTime;

    /**
     * 更新时间
     */
    @TableField(value = "update_time", fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;

    // 扩展字段（非数据库字段）
    @TableField(exist = false)
    private String questionTypeName; // 题目类型名称

    @TableField(exist = false)
    private String subjectName; // 科目名称
}

实体类体现了细致的处理：使用 @Data 注解简化模板代码；通过 @TableName 和 @TableField 实现与数据库表的映射；集成 javax.validation 注解实现参数校验；合理使用 @TableField(exist = false) 定义 DTO 扩展字段；使用 LocalDateTime 处理时间，符合 Java 8+ 规范；添加序列化接口，支持分布式场景。

DAO 层设计：MyBatis-Plus 的智能封装

数据访问层采用 MyBatis-Plus 框架，AI 生成的代码不仅包含基础 CRUD，还实现了复杂查询：

public interface QuestionMapper extends BaseMapper<Question> {
    /**
     * 按条件分页查询题目
     * 支持多条件组合查询，包含题目类型、科目、难度、关键词
     */
    @Select("<script>" +
        "SELECT q.*,qt.name as question_type_name,s.name as subject_name " +
        "FROM t_question q " +
        "LEFT JOIN t_question_type qt ON q.question_type_id = qt.id " +
        "LEFT JOIN t_subject s ON q.subject_id = s.id " +
        "<where>" +
        "<if test='questionTypeId != null'>AND q.question_type_id = #{questionTypeId}</if>" +
        "<if test='subjectId != null'>AND q.subject_id = #{subjectId}</if>" +
        "<if test='difficulty != null'>AND q.difficulty = #{difficulty}</if>" +
        "<if test='keyword != null'>AND q.content LIKE CONCAT('%',#{keyword},'%')</if>" +
        "</where>" +
        "ORDER BY q.create_time DESC" +
        "</script>")
    IPage<Question> selectPage(
        @Param("page") Page<Question> page,
        @Param("questionTypeId") Long questionTypeId,
        @Param("subjectId") Long subjectId,
        @Param("difficulty") Integer difficulty,
        @Param("keyword") String keyword);

    /**
     * 随机抽取题目（组卷核心方法）
     * 根据科目、题型、难度、数量进行随机抽题
     */
    @Select("<script>" +
        "SELECT * FROM t_question " +
        "<where>" +
        "subject_id = #{subjectId} " +
        "AND question_type_id = #{questionTypeId} " +
        "AND difficulty = #{difficulty} " +
        "</where>" +
        "ORDER BY RAND() LIMIT #{count}" +
        "</script>")
    List<Question> selectRandomQuestions(
        @Param("subjectId") Long subjectId,
        @Param("questionTypeId") Long questionTypeId,
        @Param("difficulty") Integer difficulty,
        @Param("count") Integer count);
}

DAO 层代码展现了高级查询能力：继承 BaseMapper 获得基础 CRUD 操作，减少重复代码；使用 MyBatis 动态 SQL 实现多条件查询；专门设计 selectRandomQuestions 方法支持智能组卷；分页查询包含关联表信息，减少 N+1 查询问题；参数命名规范，与业务逻辑保持一致。

Service 层设计：事务管理与业务逻辑

Service 层是业务逻辑核心，AI 生成的代码包含完整的事务控制和业务规则：

@Service
@Slf4j
public class ExamServiceImpl implements ExamService {
    @Autowired
    private ExamRecordMapper examRecordMapper;
    @Autowired
    private PaperMapper paperMapper;
    @Autowired
    private QuestionMapper questionMapper;
    @Autowired
    private AnswerMapper answerMapper;
    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    /**
     * 开始考试（带事务控制）
     */
    @Override
    @Transactional(rollbackFor = Exception.class)
    public ExamStartVO startExam(Long paperId, Long userId) {
        // 1. 验证试卷状态
        Paper paper = paperMapper.selectById(paperId);
        if (paper == null) {
            throw new BusinessException("试卷不存在");
        }
        if (paper.getStatus() != 1) {
            throw new BusinessException("试卷未发布或已过期");
        }

        // 2. 检查是否已参加过考试
        QueryWrapper<ExamRecord> queryWrapper = new QueryWrapper<>();
        queryWrapper.eq("user_id", userId)
                .eq("paper_id", paperId)
                .in("status", 1, 2); // 进行中或已完成
        ExamRecord existRecord = examRecordMapper.selectOne(queryWrapper);
        if (existRecord != null) {
            if (existRecord.getStatus() == 1) {
                throw new BusinessException("您有未完成的考试，请继续作答");
            } else {
                throw new BusinessException("您已参加过该考试，不能重复考试");
            }
        }

        // 3. 创建考试记录
        ExamRecord examRecord = new ExamRecord();
        examRecord.setPaperId(paperId);
        examRecord.setUserId(userId);
        examRecord.setStartTime(LocalDateTime.now());
        examRecord.setStatus(1); // 进行中
        examRecord.setIpAddress(IpUtils.getIpAddr());
        examRecordMapper.insert(examRecord);

        // 4. 获取试卷题目
        List<Question> questions = questionMapper.selectByPaperId(paperId);
        if (CollectionUtils.isEmpty(questions)) {
            throw new BusinessException("试卷未配置题目，请联系管理员");
        }

        // 5. 缓存考试信息到 Redis，设置过期时间（考试时长 +5 分钟缓冲）
        String examKey = "exam:record:" + examRecord.getId();
        redisTemplate.opsForValue().set(examKey, examRecord, paper.getDuration() + 5, TimeUnit.MINUTES);

        // 6. 构建返回结果
        ExamStartVO result = new ExamStartVO();
        result.setExamId(examRecord.getId());
        result.setPaperId(paperId);
        result.setPaperName(paper.getName());
        result.setDuration(paper.getDuration());
        result.setStartTime(examRecord.getStartTime());
        result.setQuestions(questions);
        log.info("用户 [{}] 开始考试 [{}]，试卷 [{}]", userId, examRecord.getId(), paperId);
        return result;
    }

    /**
     * 提交答案并自动判分（核心业务逻辑）
     */
    @Override
    @Transactional(rollbackFor = Exception.class)
    public ExamResultVO submitAnswer(Long examId, Long userId, List<AnswerDTO> answerList) {
        // 1. 验证考试状态
        ExamRecord examRecord = examRecordMapper.selectById(examId);
        if (examRecord == null) {
            throw new BusinessException("考试记录不存在");
        }
        if (!examRecord.getUserId().equals(userId)) {
            throw new BusinessException("无权操作他人考试记录");
        }
        if (examRecord.getStatus() != 1) {
            throw new BusinessException("考试已结束或已提交");
        }

        // 2. 获取试卷信息
        Paper paper = paperMapper.selectById(examRecord.getPaperId());
        if (paper == null) {
            throw new BusinessException("试卷信息不存在");
        }

        // 3. 保存答案并计算得分
        BigDecimal totalScore = BigDecimal.ZERO;
        List<Answer> answers = new ArrayList<>();
        for (AnswerDTO dto : answerList) {
            // 查询题目信息
            Question question = questionMapper.selectById(dto.getQuestionId());
            if (question == null) {
                continue;
            }

            // 创建答案记录
            Answer answer = new Answer();
            answer.setExamId(examId);
            answer.setQuestionId(dto.getQuestionId());
            answer.setUserId(userId);
            answer.setUserAnswer(dto.getUserAnswer());
            answer.setCreateTime(LocalDateTime.now());

            // 自动判分（不同题型有不同判分规则）
            BigDecimal score = BigDecimal.ZERO;
            if (question.getQuestionTypeId() == 3) { // 判断题
                if (Objects.equals(dto.getUserAnswer(), question.getAnswer())) {
                    score = BigDecimal.valueOf(question.getScore());
                }
            } else if (question.getQuestionTypeId() == 1) { // 单选题
                if (Objects.equals(dto.getUserAnswer(), question.getAnswer())) {
                    score = BigDecimal.valueOf(question.getScore());
                }
            } else if (question.getQuestionTypeId() == 2) { // 多选题（按正确比例得分）
                String[] userAnswers = dto.getUserAnswer().split(",");
                String[] correctAnswers = question.getAnswer().split(",");
                int correctCount = 0;
                for (String userAns : userAnswers) {
                    if (Arrays.asList(correctAnswers).contains(userAns)) {
                        correctCount++;
                    } else {
                        // 多选错选不得分
                        correctCount = 0;
                        break;
                    }
                }
                // 部分正确得分
                if (correctCount > 0 && correctCount < correctAnswers.length) {
                    score = BigDecimal.valueOf(question.getScore())
                            .multiply(BigDecimal.valueOf(correctCount))
                            .divide(BigDecimal.valueOf(correctAnswers.length), 1, RoundingMode.HALF_UP);
                } else if (correctCount == correctAnswers.length) {
                    score = BigDecimal.valueOf(question.getScore());
                }
            }
            answer.setScore(score);
            answers.add(answer);
            totalScore = totalScore.add(score);
        }

        // 4. 批量保存答案
        if (!answers.isEmpty()) {
            answerMapper.batchInsert(answers);
        }

        // 5. 更新考试记录
        examRecord.setEndTime(LocalDateTime.now());
        examRecord.setStatus(2); // 已完成
        examRecord.setScore(totalScore);
        examRecordMapper.updateById(examRecord);

        // 6. 删除 Redis 缓存
        String examKey = "exam:record:" + examId;
        redisTemplate.delete(examKey);

        // 7. 构建返回结果
        ExamResultVO result = new ExamResultVO();
        result.setExamId(examId);
        result.setTotalScore(totalScore);
        result.setPassScore(paper.getPassScore());
        result.setIsPass(totalScore.compareTo(paper.getPassScore()) >= 0);
        result.setEndTime(examRecord.getEndTime());
        log.info("用户 [{}] 完成考试 [{}]，得分 [{}]", userId, examId, totalScore);
        return result;
    }

    /**
     * 随机组卷算法（智能组卷核心）
     */
    @Override
    public Long generateRandomPaper(PaperGenerateDTO dto) {
        // 1. 参数校验
        if (dto.getSubjectId() == null) {
            throw new BusinessException("请选择考试科目");
        }
        if (CollectionUtils.isEmpty(dto.getQuestionTypeList())) {
            throw new BusinessException("请选择题目类型");
        }

        // 2. 创建试卷基本信息
        Paper paper = new Paper();
        paper.setName(dto.getPaperName());
        paper.setSubjectId(dto.getSubjectId());
        paper.setDuration(dto.getDuration());
        paper.setPassScore(dto.getPassScore());
        paper.setStatus(0); // 未发布
        paper.setCreateBy(dto.getCreateBy());
        paperMapper.insert(paper);
        Long paperId = paper.getId();

        // 3. 按题型和难度随机抽题
        List<PaperQuestion> paperQuestions = new ArrayList<>();
        int sort = 1;
        for (QuestionTypeDTO type : dto.getQuestionTypeList()) {
            // 按难度分布抽题
            for (DifficultyDTO difficulty : type.getDifficultyList()) {
                List<Question> questions = questionMapper.selectRandomQuestions(
                        dto.getSubjectId(), type.getQuestionTypeId(), difficulty.getDifficulty(), difficulty.getCount()
                );
                // 处理抽题不足的情况
                if (questions.size() < difficulty.getCount()) {
                    log.warn("题目不足：科目 [{}],题型 [{}],难度 [{}],需求 [{}],实际 [{}]", dto.getSubjectId(), type.getQuestionTypeId(), difficulty.getDifficulty(), difficulty.getCount(), questions.size());
                }
                // 添加到试卷
                for (Question q : questions) {
                    PaperQuestion pq = new PaperQuestion();
                    pq.setPaperId(paperId);
                    pq.setQuestionId(q.getId());
                    pq.setScore(q.getScore());
                    pq.setSort(sort++);
                    paperQuestions.add(pq);
                }
            }
        }

        // 4. 保存试卷题目关联关系
        if (!paperQuestions.isEmpty()) {
            paperQuestionMapper.batchInsert(paperQuestions);
            // 5. 计算试卷总分
            BigDecimal totalScore = paperQuestions.stream()
                    .map(PaperQuestion::getScore)
                    .reduce(BigDecimal.ZERO, BigDecimal::add);
            paper.setTotalScore(totalScore);
            paperMapper.updateById(paper);
        }
        log.info("生成随机试卷 [{}]，题目数量 [{}]", paperId, paperQuestions.size());
        return paperId;
    }
}

Service 层代码体现了企业级应用的核心特性：使用 @Transactional 注解保证事务一致性；完善的参数校验和异常处理（自定义 BusinessException）；复杂业务逻辑实现，如多选题的按比例计分规则；结合 Redis 实现考试状态缓存和过期控制；批量操作优化提升性能；详细的日志记录便于问题排查；面向接口编程，通过 VO/DTO 分离数据传输对象。

Controller 层设计：RESTful 接口与统一响应

控制器层实现了 RESTful 风格的 API 设计，包含完整的请求处理流程：

@RestController
@RequestMapping("/api/exam")
@Slf4j
public class ExamController {
    @Autowired
    private ExamService examService;
    @Autowired
    private AnswerService answerService;

    /**
     * 开始考试接口
     */
    @PostMapping("/start")
    public Result<ExamStartVO> startExam(@Valid @RequestBody ExamStartDTO dto, HttpServletRequest request) {
        try {
            // 获取当前登录用户 ID（实际项目中从 Token 中解析）
            Long userId = SecurityUtils.getCurrentUserId();
            ExamStartVO result = examService.startExam(dto.getPaperId(), userId);
            return Result.success(result);
        } catch (BusinessException e) {
            log.warn("开始考试失败：{}", e.getMessage());
            return Result.fail(e.getMessage());
        } catch (Exception e) {
            log.error("开始考试异常", e);
            return Result.error("系统异常，请稍后重试");
        }
    }

    /**
     * 提交答案接口
     */
    @PostMapping("/submit")
    public Result<ExamResultVO> submitAnswer(@Valid @RequestBody ExamSubmitDTO dto) {
        try {
            Long userId = SecurityUtils.getCurrentUserId();
            ExamResultVO result = examService.submitAnswer(dto.getExamId(), userId, dto.getAnswerList());
            return Result.success(result);
        } catch (BusinessException e) {
            log.warn("提交答案失败：{}", e.getMessage());
            return Result.fail(e.getMessage());
        } catch (Exception e) {
            log.error("提交答案异常", e);
            return Result.error("系统异常，请稍后重试");
        }
    }

    /**
     * 获取考试详情接口
     */
    @GetMapping("/{examId}/detail")
    public Result<ExamDetailVO> getExamDetail(@PathVariable Long examId) {
        try {
            Long userId = SecurityUtils.getCurrentUserId();
            ExamDetailVO result = examService.getExamDetail(examId, userId);
            return Result.success(result);
        } catch (BusinessException e) {
            log.warn("获取考试详情失败：{}", e.getMessage());
            return Result.fail(e.getMessage());
        } catch (Exception e) {
            log.error("获取考试详情异常", e);
            return Result.error("系统异常，请稍后重试");
        }
    }

    /**
     * 随机组卷接口
     */
    @PostMapping("/paper/random")
    public Result<Long> generateRandomPaper(@Valid @RequestBody PaperGenerateDTO dto) {
        try {
            Long userId = SecurityUtils.getCurrentUserId();
            dto.setCreateBy(userId);
            Long paperId = examService.generateRandomPaper(dto);
            return Result.success(paperId);
        } catch (BusinessException e) {
            log.warn("随机组卷失败：{}", e.getMessage());
            return Result.fail(e.getMessage());
        } catch (Exception e) {
            log.error("随机组卷异常", e);
            return Result.error("系统异常，请稍后重试");
        }
    }

    /**
     * 监控考试状态（防作弊）
     */
    @PostMapping("/monitor")
    public Result<Boolean> monitorExamStatus(@RequestBody ExamMonitorDTO dto) {
        try {
            Long userId = SecurityUtils.getCurrentUserId();
            examService.updateExamStatus(dto.getExamId(), userId, dto.getStatus());
            return Result.success(true);
        } catch (Exception e) {
            log.error("监控考试状态异常", e);
            return Result.success(false);
        }
    }
}

Controller 层实现了规范的 API 设计：采用 RESTful 风格的 URL 设计，使用合适的 HTTP 方法；统一的响应格式 Result，包含状态码、消息和数据；使用 @Valid 注解进行请求参数校验；完善的异常处理机制，区分业务异常和系统异常；日志分级记录便于问题定位；安全控制；清晰的接口命名和职责划分。

前端代码：Vue 组件与实时交互

生成的前端代码基于 Vue 和 Element UI，实现了丰富的交互功能：

<template>
    <div>
        <!-- 考试头部信息 -->
        <el-card>
            <div>
                <div>
                    <h2>{{ paperName }}</h2>
                    <p>考试时长：{{ duration }}分钟</p>
                </div>
                <div :class="{ warning: remainingTime < 5 * 60, danger: remainingTime < 60 }">
                    <i></i>
                    <span>剩余时间：{{ formatTime(remainingTime) }}</span>
                </div>
                <el-button type="primary" @click="handleSubmit" :loading="submitting">
                    交卷
                </el-button>
            </div>
        </el-card>

        <!-- 题目区域 -->
        <el-card>
            <div>
                <el-button v-for="(q, index) in questions" :key="q.id" :class="{ 'question-btn': true, 'answered': answeredQuestions.includes(q.id), 'current': currentQuestionIndex === index }"
                           @click="goToQuestion(index)">
                    {{ index + 1 }}
                </el-button>
            </div>
            <div>
                <div v-if="currentQuestion">
                    <div>
                        <span>
                            {{ getQuestionTypeName(currentQuestion.questionTypeId) }} ({{ currentQuestion.score }}分)
                        </span>
                        <h3>{{ currentQuestionIndex + 1 }}. {{ currentQuestion.content }}</h3>
                    </div>
                    <div v-if="currentQuestion.questionTypeId !== 3">
                        <!-- 单选题/多选题选项 -->
                        <el-radio-group v-if="currentQuestion.questionTypeId === 1" v-model="currentAnswer" @change="handleAnswerChange">
                            <el-radio :label="'A'">A. {{ currentQuestion.optionA }}</el-radio>
                            <el-radio :label="'B'">B. {{ currentQuestion.optionB }}</el-radio>
                            <el-radio :label="'C'">C. {{ currentQuestion.optionC }}</el-radio>
                            <el-radio :label="'D'">D. {{ currentQuestion.optionD }}</el-radio>
                        </el-radio-group>
                        <el-checkbox-group v-if="currentQuestion.questionTypeId === 2" v-model="currentAnswer" @change="handleAnswerChange">
                            <el-checkbox :label="'A'">A. {{ currentQuestion.optionA }}</el-checkbox>
                            <el-checkbox :label="'B'">B. {{ currentQuestion.optionB }}</el-checkbox>
                            <el-checkbox :label="'C'">C. {{ currentQuestion.optionC }}</el-checkbox>
                            <el-checkbox :label="'D'">D. {{ currentQuestion.optionD }}</el-checkbox>
                        </el-checkbox-group>
                    </div>
                    <div v-if="currentQuestion.questionTypeId === 3">
                        <!-- 判断题 -->
                        <el-radio-group v-model="currentAnswer" @change="handleAnswerChange">
                            <el-radio :label="'正确'">正确</el-radio>
                            <el-radio :label="'错误'">错误</el-radio>
                        </el-radio-group>
                    </div>
                </div>
                <div>
                    <el-button @click="prevQuestion" :disabled="currentQuestionIndex === 0">上一题</el-button>
                    <el-button @click="nextQuestion" :disabled="currentQuestionIndex === questions.length - 1">下一题</el-button>
                </div>
            </div>
        </el-card>
    </div>
</template>

<script>
import { mapGetters } from 'vuex'
import { monitorExamStatus } from '@/api/exam'

export default {
    name: 'OnlineExam',
    props: {
        examId: {
            type: Number,
            required: true
        },
        paperId: {
            type: Number,
            required: true
        }
    },
    data() {
        return {
            paperName: '',
            duration: 0,
            questions: [],
            currentQuestionIndex: 0,
            answers: {}, // 存储答案 { questionId: answer }
            answeredQuestions: [],
            remainingTime: 0,
            timer: null,
            submitting: false,
            lastActiveTime: new Date().getTime(),
            cheatWarningCount: 0
        }
    },
    computed: {
        currentQuestion() {
            return this.questions[this.currentQuestionIndex]
        },
        currentAnswer: {
            get() {
                const questionId = this.currentQuestion?.id
                return questionId ? this.answers[questionId] || (this.currentQuestion.questionTypeId === 2 ? [] : '') : ''
            },
            set(val) {
                const questionId = this.currentQuestion?.id
                if (questionId) {
                    this.answers[questionId] = val
                    if (!this.answeredQuestions.includes(questionId)) {
                        this.answeredQuestions.push(questionId)
                    }
                }
            }
        },
        ...mapGetters(['userInfo'])
    },
    created() {
        this.loadExamData()
        // 监听页面可见性变化（防作弊）
        document.addEventListener('visibilitychange', this.handleVisibilityChange)
        // 监听窗口焦点变化
        window.addEventListener('blur', this.handleWindowBlur)
        window.addEventListener('focus', this.handleWindowFocus)
    },
    beforeDestroy() {
        if (this.timer) {
            clearInterval(this.timer)
        }
        document.removeEventListener('visibilitychange', this.handleVisibilityChange)
        window.removeEventListener('blur', this.handleWindowBlur)
        window.removeEventListener('focus', this.handleWindowFocus)
    },
    methods: {
        // 加载考试数据
        async loadExamData() {
            try {
                const res = await this.$api.exam.getExamDetail(this.examId)
                if (res.success) {
                    this.paperName = res.data.paperName
                    this.duration = res.data.duration
                    this.questions = res.data.questions
                    this.remainingTime = this.duration * 60
                    this.startTimer()
                }
            } catch (error) {
                this.$message.error('加载考试数据失败')
            }
        },
        // 开始倒计时
        startTimer() {
            this.timer = setInterval(() => {
                this.remainingTime--
                // 每分钟向服务器汇报一次状态
                if (this.remainingTime % 60 === 0) {
                    this.reportExamStatus('normal')
                }
                // 时间到自动交卷
                if (this.remainingTime <= 0) {
                    this.handleSubmit(true)
                }
            }, 1000)
        },
        // 格式化时间
        formatTime(seconds) {
            const mins = Math.floor(seconds / 60)
            const secs = seconds % 60
            return `${mins.toString().padStart(2, '0')}:${secs.toString().padStart(2, '0')}`
        },
        // 处理答案变更
        handleAnswerChange() {
            // 每 30 秒自动保存一次答案
            this.saveAnswer()
        },
        // 自动保存答案
        async saveAnswer() {
            try {
                await this.$api.exam.saveAnswer({
                    examId: this.examId,
                    questionId: this.currentQuestion.id,
                    userAnswer: this.currentAnswer
                })
            } catch (error) {
                console.error('保存答案失败', error)
            }
        },
        // 上一题
        prevQuestion() {
            if (this.currentQuestionIndex > 0) {
                this.currentQuestionIndex--
            }
        },
        // 下一题
        nextQuestion() {
            if (this.currentQuestionIndex < this.questions.length - 1) {
                this.currentQuestionIndex++
            }
        },
        // 跳转到指定题目
        goToQuestion(index) {
            this.currentQuestionIndex = index
        },
        // 交卷处理
        async handleSubmit(autoSubmit = false) {
            if (!autoSubmit && !confirm('确定要交卷吗？交卷后无法修改答案！')) {
                return
            }
            this.submitting = true
            try {
                const answerList = this.questions.map(q => ({
                    questionId: q.id,
                    userAnswer: this.answers[q.id] || ''
                }))
                const res = await this.$api.exam.submitAnswer({
                    examId: this.examId,
                    answerList: answerList
                })
                if (res.success) {
                    this.$message.success('交卷成功！')
                    // 跳转到成绩页面
                    this.$router.push({ path: '/exam/result', query: { examId: this.examId } })
                } else {
                    this.$message.error(res.message || '交卷失败')
                    this.submitting = false
                }
            } catch (error) {
                this.$message.error('交卷失败，请重试')
                this.submitting = false
            }
        },
        // 获取题目类型名称
        getQuestionTypeName(typeId) {
            const typeMap = {
                1: '单选题',
                2: '多选题',
                3: '判断题'
            }
            return typeMap[typeId] || '未知题型'
        },
        // 汇报考试状态
        async reportExamStatus(status) {
            try {
                await monitorExamStatus({
                    examId: this.examId,
                    status: status
                })
            } catch (error) {
                console.error('汇报考试状态失败', error)
            }
        },
        // 处理页面可见性变化（防作弊）
        handleVisibilityChange() {
            if (document.hidden) {
                this.reportExamStatus('hidden')
                this.cheatWarningCount++
                if (this.cheatWarningCount >= 3) {
                    this.$message.warning('检测到多次切换页面，将自动交卷！')
                    setTimeout(() => this.handleSubmit(true), 5000)
                } else {
                    this.$message.warning(`检测到页面切换，已记录 (${this.cheatWarningCount}/3)`)
                }
            }
        },
        // 处理窗口失去焦点
        handleWindowBlur() {
            this.lastActiveTime = new Date().getTime()
        },
        // 处理窗口获得焦点
        handleWindowFocus() {
            const now = new Date().getTime()
            // 如果失去焦点超过 30 秒，视为作弊
            if (now - this.lastActiveTime > 30 * 1000) {
                this.reportExamStatus('blur_timeout')
                this.cheatWarningCount++
                this.$message.warning(`检测到长时间离开考试页面，已记录 (${this.cheatWarningCount}/3)`)
            }
        }
    }
}
</script>

<style scoped>
.exam-container {
    padding: 20px;
}
.exam-header {
    margin-bottom: 20px;
}
.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.timer {
    font-size: 16px;
    font-weight: bold;
}
.timer.warning {
    color: #e6a23c;
}
.timer.danger {
    color: #f56c6c;
}
.questions-container {
    display: flex;
    gap: 20px;
}
.question-nav {
    width: 120px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.question-btn {
    width: 30px;
    height: 30px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}
.question-btn.answered {
    background-color: #67c23a;
    color: white;
}
.question-btn.current {
    background-color: #409eff;
    color: white;
}
.question-content {
    flex: 1;
}
.question-item {
    margin-bottom: 30px;
}
.question-type {
    display: inline-block;
    padding: 3px 8px;
    background-color: #f5f7fa;
    border-radius: 4px;
    margin-right: 10px;
}
.option-item {
    display: block;
    margin-bottom: 10px;
    padding: 8px 10px;
    border-radius: 4px;
    transition: all 0.2s;
}
.option-item:hover {
    background-color: #f5f7fa;
}
.question-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}
</style>

前端代码实现了丰富的交互功能：完整的考试流程，包括题目导航、答题、交卷；实时倒计时功能，支持自动交卷；防作弊机制，监控页面切换、窗口焦点变化；答案自动保存，避免意外丢失；响应式布局，适配不同屏幕尺寸；清晰的视觉反馈，已答题标记、当前题标记；不同题型的差异化展示。

开发效率对比：AI 生成代码带来的质变

通过 AI 辅助开发在线考试系统，深刻体会到了智能开发工具的革命性影响：

代码质量对比：

• 传统开发：需要手动处理事务、异常、缓存等复杂逻辑，容易出现疏漏
• AI 生成代码：内置完整的事务管理、异常处理、缓存策略和安全控制
• 可维护性：AI 生成的代码遵循统一规范，注释完整，架构清晰

功能完整性： AI 生成的系统不仅实现了基础功能，还包含了许多高级特性：

• 防作弊机制（页面监控、切屏检测）
• 智能组卷算法（按难度、题型自动抽题）
• 复杂计分规则（多选题部分得分逻辑）
• 分布式缓存（Redis 存储考试状态）

总结：AI 驱动的开发新范式

AI 工具彻底改变了开发认知 —— 它不仅是一个代码生成工具，更是一个全流程的开发助手。通过分析本次生成的在线考试系统代码，可以发现几个显著特点：

1. 架构完整性：严格遵循三层架构设计，各层职责清晰，依赖关系合理

2. 业务深度：针对考试场景设计了完整的业务逻辑，包括复杂的计分规则和组卷算法

3. 技术先进性：整合了 Spring Boot、MyBatis-Plus、Redis 等主流技术栈

4. 安全性考虑：包含权限控制、防作弊机制、数据校验等安全措施

5. 可扩展性：代码结构松耦合，便于后续功能扩展和维护

对于开发者而言，这是一个绝佳的学习工具 —— 通过研究 AI 生成的高质量代码，可以掌握许多企业级开发的最佳实践。对于企业来说，这种智能开发工具将大幅降低开发成本，缩短项目周期。

未来的软件开发，必将是 "人类定义需求，AI 实现细节" 的协作模式。在 AI 的助力下，我们终于可以从重复劳动中解放出来，将更多精力投入到创意和创新中去。