在线图书借阅平台设计与实现：AI 辅助开发实战

Book.java（图书实体）

package com.student.library.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import java.time.LocalDateTime;

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("book")
public class Book {
    @TableId(type = IdType.AUTO)
    private Long bookNo;
    private String bookName;
    private String author;
    private Long categoryId;
    private String publisher;
    private LocalDateTime publishDate;
    private Integer totalCount;
    private Integer availableCount;
    private String description;
}

（2）DTO 包：数据传输对象

BorrowBookDTO.java（借阅请求）

package com.student.library.dto;

import jakarta.validation.constraints.NotNull;
import lombok.Data;

@Data
public class BorrowBookDTO {
    @NotNull(message = "学生 ID 不能为空")
    private Long studentId;
    
    @NotNull(message = "图书编号不能为空")
    private Long bookNo;
    
    @NotNull(message = "借阅天数不能为空")
    private Integer borrowDays = 30;
}

（3）VO 包：视图对象

BookDetailVO.java（图书详情）

package com.student.library.vo;

import lombok.Data;
import java.time.LocalDateTime;

@Data
public class BookDetailVO {
    private Long bookNo;
    private String bookName;
    private String author;
    private String categoryName;
    private String publisher;
    private LocalDateTime publishDate;
    private Integer availableCount;
    private String description;
    private Boolean canBorrow;
}

（4）Service 包：业务逻辑实现

BorrowServiceImpl.java（借阅服务）

package com.student.library.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.student.library.dto.BorrowBookDTO;
import com.student.library.entity.Book;
import com.student.library.entity.BorrowRecord;
import com.student.library.entity.User;
import com.student.library.mapper.BookMapper;
import com.student.library.mapper.BorrowRecordMapper;
import com.student.library.mapper.UserMapper;
import com.student.library.service.BorrowService;
import com.student.library.vo.BorrowRecordVO;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import java.time.LocalDate;
import java.time.temporal.ChronoUnit;
import java.util.List;
import java.util.stream.Collectors;

@Slf4j
@Service
@RequiredArgsConstructor
public class BorrowServiceImpl extends ServiceImpl<BorrowRecordMapper, BorrowRecord> implements BorrowService {
    private final BorrowRecordMapper borrowRecordMapper;
    private final BookMapper bookMapper;
    private final UserMapper userMapper;

    @Override
    @Transactional
    public BorrowRecord borrowBook(BorrowBookDTO borrowBookDTO) {
        log.info("学生借阅图书：学生 ID={}, 图书编号={}, 借阅天数={}", 
                 borrowBookDTO.getStudentId(), borrowBookDTO.getBookNo(), borrowBookDTO.getBorrowDays());

        // 1. 校验学生身份
        User student = userMapper.selectById(borrowBookDTO.getStudentId());
        if (student == null || student.getRole() != 0) {
            throw new RuntimeException("无效的学生账号，无法借阅图书");
        }

        // 2. 校验图书状态
        Book book = bookMapper.selectById(borrowBookDTO.getBookNo());
        if (book == null) {
            throw new RuntimeException("该图书不存在");
        }
        if (book.getAvailableCount() <= 0) {
            throw new RuntimeException("该图书已无库存，可尝试预约");
        }

        // 3. 生成借阅记录
        BorrowRecord borrowRecord = new BorrowRecord();
        borrowRecord.setStudentId(borrowBookDTO.getStudentId());
        borrowRecord.setBookNo(borrowBookDTO.getBookNo());
        borrowRecord.setBorrowDate(LocalDate.now());
        borrowRecord.setDueDate(LocalDate.now().plusDays(borrowBookDTO.getBorrowDays()));
        borrowRecord.setReturnStatus(0);

        // 4. 更新库存
        book.setAvailableCount(book.getAvailableCount() - 1);
        bookMapper.updateById(book);

        save(borrowRecord);
        return borrowRecord;
    }

    @Override
    @Transactional
    public BorrowRecord renewBook(Long recordId) {
        BorrowRecord record = getById(recordId);
        if (record == null) {
            throw new RuntimeException("借阅记录不存在");
        }
        if (record.getReturnStatus() == 1) {
            throw new RuntimeException("该图书已归还，无需续借");
        }
        if (LocalDate.now().isAfter(record.getDueDate())) {
            throw new RuntimeException("图书已超期，请先归还并处理罚款");
        }
        if (record.getRenewCount() >= 1) {
            throw new RuntimeException("该图书已续借 1 次，无法再次续借");
        }

        record.setDueDate(record.getDueDate().plusDays(30));
        record.setRenewCount(record.getRenewCount() + 1);
        updateById(record);
        return record;
    }

    @Override
    public List<BorrowRecordVO> getStudentBorrowRecords(Long studentId) {
        List<BorrowRecord> recordList = lambdaQuery()
                .eq(BorrowRecord::getStudentId, studentId)
                .eq(BorrowRecord::getReturnStatus, 0)
                .list();

        return recordList.stream().map(record -> {
            BorrowRecordVO vo = new BorrowRecordVO();
            BeanUtils.copyProperties(record, vo);
            Book book = bookMapper.selectById(record.getBookNo());
            vo.setBookName(book.getBookName());
            vo.setAuthor(book.getAuthor());

            long daysLeft = ChronoUnit.DAYS.between(LocalDate.now(), record.getDueDate());
            vo.setDaysLeft((int) daysLeft);
            if (daysLeft < 0) {
                vo.setOverdueReminder("已超期" + (-daysLeft) + "天，请尽快归还");
            } else if (daysLeft <= 3) {
                vo.setOverdueReminder("即将超期，剩余" + daysLeft + "天");
            } else {
                vo.setOverdueReminder("正常借阅中");
            }
            return vo;
        }).collect(Collectors.toList());
    }
}

四、网页展示

前端采用 Bootstrap 实现响应式布局，适配电脑端场景。

1. 图书查询页

顶部搜索栏支持按书名、作者检索，左侧分类筛选，中间卡片式展示图书列表。库存为 0 时显示红色标签，支持分页。

<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <title>图书查询 - 校园图书馆系统</title>
    <link href="https://cdn.jsdelivr.net/npm/[email protected]/dist/css/bootstrap.min.css" rel="stylesheet">
    <style>
        .category-item:hover, .category-item.active { background-color: #0d6efd; color: white !important; }
        .book-card:hover { transform: translateY(-5px); box-shadow: 0 10px 20px rgba(0,0,0,0.1); }
        .no-stock { position: absolute; top: 10px; right: 10px; }
    </style>
</head>
<body>
<nav class="navbar navbar-expand-lg navbar-dark bg-primary mb-4">
    <div class="container"><a class="navbar-brand" href="#">校园图书馆</a></div>
</nav>
<div class="container">
    <h3 class="mb-4">图书查询</h3>
    <div class="row mb-4">
        <div class="col-md-8 offset-md-2">
            <div class="input-group">
                <input type="text" class="form-control" placeholder="请输入书名或作者进行搜索..." id="searchInput">
                <button class="btn btn-primary" type="button" id="searchBtn">搜索</button>
            </div>
        </div>
    </div>
    <div class="row">
        <div class="col-md-3 mb-4">
            <div class="card">
                <div class="card-header bg-light"><h5 class="mb-0">图书分类</h5></div>
                <div class="list-group list-group-flush">
                    <a href="#" class="list-group-item list-group-item-action category-item active">全部图书</a>
                    <a href="#" class="list-group-item list-group-item-action category-item">计算机类</a>
                    <a href="#" class="list-group-item list-group-item-action category-item">文学类</a>
                </div>
            </div>
        </div>
        <div class="col-md-9">
            <!-- 图书卡片示例 -->
            <div class="col-md-4 mb-4">
                <div class="card book-card h-100 position-relative">
                    <img src="https://picsum.photos/id/24/300/400" class="card-img-top" alt="Java 编程思想">
                    <div class="card-body">
                        <h5 class="card-title">Java 编程思想</h5>
                        <p class="card-text text-muted">作者：Bruce Eckel</p>
                        <p class="card-text"><small>剩余可借：<span class="text-success">5</span>/10</small></p>
                        <a href="#" class="btn btn-primary btn-sm w-100">查看详情</a>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>
<script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/js/bootstrap.bundle.min.js"></script>
</body>
</html>

2. 借阅记录页

表格展示未归还记录，列包含图书名称、到期时间、剩余天数。剩余天数小于 3 天显示红色预警，支持续借与归还预约。

3. 图书管理页

管理员端页面，支持添加、编辑、下架图书。库存低于 1/3 时显示黄色提示，便于补充馆藏。

五、优化与调试

1. 核心优化点

• 密码加密：集成 Spring Security 的 BCrypt 加密，避免明文存储密码。
• 超期提醒：在 Service 层计算剩余天数，前端根据数值动态渲染警告信息。
• 分类管理：补充 CategoryController 和 Service，支持管理员灵活维护图书分类。

2. 常见问题解决

• 数据库连接失败：检查 application.yml 中的 MySQL 密码配置是否正确。
• 库存未减少：确认 borrowBook 方法中是否调用了 bookMapper.updateById(book) 更新库存。

六、总结

本项目展示了如何利用 AI 辅助工具快速构建功能完整的图书管理系统。通过规范的需求拆解与代码生成，有效降低了基础代码编写成本，使开发者能更专注于核心业务逻辑的实现。后续可进一步扩展预约功能、罚款系统等模块，以适应更复杂的实际场景。