基于飞算 JavaAI 的在线教育平台设计与实现

Course.java（课程实体）

package com.student.education.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("course")
public class Course {
    @TableId(type = IdType.AUTO)
    private Long id;
    
    private String courseName;
    private String category;
    private Long teacherId;
    private String description;
    private String coverUrl;
    private LocalDateTime createTime;
    private Integer status;
}

（2）DTO 包：数据传输对象

CourseAddDTO.java（课程创建请求）

package com.student.education.dto;

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

@Data
public class CourseAddDTO {
    @NotBlank(message = "课程名称不能为空")
    private String courseName;
    
    @NotBlank(message = "课程分类不能为空")
    private String category;
    
    @NotNull(message = "创建老师 ID 不能为空")
    private Long teacherId;
    
    private String description;
    private Integer status;
}

（3）VO 包：视图对象

CourseDetailVO.java（课程详情）

package com.student.education.vo;

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

@Data
public class CourseDetailVO {
    private Long courseId;
    private String courseName;
    private String category;
    private String teacherName;
    private String description;
    private String coverUrl;
    private List<VideoVO> videoList;
    private List<HomeworkSimpleVO> homeworkList;
    private Boolean isEnrolled;
}

（4）Service 包：业务逻辑实现

CourseServiceImpl.java（课程服务）

package com.student.education.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.student.education.dto.CourseAddDTO;
import com.student.education.entity.Course;
import com.student.education.entity.CourseEnroll;
import com.student.education.entity.User;
import com.student.education.mapper.CourseEnrollMapper;
import com.student.education.mapper.CourseMapper;
import com.student.education.mapper.UserMapper;
import com.student.education.service.CourseService;
import com.student.education.vo.CourseDetailVO;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Slf4j
@Service
@RequiredArgsConstructor
public class CourseServiceImpl extends ServiceImpl<CourseMapper, Course> implements CourseService {
    private final CourseMapper courseMapper;
    private final UserMapper userMapper;
    private final CourseEnrollMapper courseEnrollMapper;

    @Override
    @Transactional
    public Course addCourse(CourseAddDTO courseAddDTO) {
        log.info("老师创建课程：老师 ID={}, 课程名称={}", courseAddDTO.getTeacherId(), courseAddDTO.getCourseName());
        
        // 1. 校验老师身份
        User teacher = userMapper.selectById(courseAddDTO.getTeacherId());
        if (teacher == null || teacher.getRole() != 1) {
            throw new RuntimeException("无效的老师账号，无法创建课程");
        }
        
        // 2. DTO 转实体
        Course course = new Course();
        BeanUtils.copyProperties(courseAddDTO, course);
        if (course.getCoverUrl() == null || course.getCoverUrl().isEmpty()) {
            course.setCoverUrl("/static/images/default-course-cover.png");
        }
        course.setCreateTime(java.time.LocalDateTime.now());
        
        save(course);
        log.info("课程创建成功：课程 ID={}", course.getId());
        return course;
    }

    @Override
    @Transactional
    public void enrollCourse(Long studentId, Long courseId) {
        log.info("学生报名课程：学生 ID={}, 课程 ID={}", studentId, courseId);
        
        // 1. 校验学生身份
        User student = userMapper.selectById(studentId);
        if (student == null || student.getRole() != 0) {
            throw new RuntimeException("无效的学生账号，无法报名课程");
        }
        
        // 2. 校验课程状态
        Course course = getById(courseId);
        if (course == null) {
            throw new RuntimeException("课程不存在");
        }
        if (course.getStatus() != 1) {
            throw new RuntimeException("课程未发布，暂无法报名");
        }
        
        // 3. 校验是否已报名
        CourseEnroll existingEnroll = courseEnrollMapper.selectByStudentAndCourse(studentId, courseId);
        if (existingEnroll != null) {
            throw new RuntimeException("已报名该课程，无需重复操作");
        }
        
        // 4. 保存报名记录
        CourseEnroll courseEnroll = new CourseEnroll();
        courseEnroll.setStudentId(studentId);
        courseEnroll.setCourseId(courseId);
        courseEnroll.setEnrollTime(java.time.LocalDateTime.now());
        courseEnrollMapper.insert(courseEnroll);
        log.info("学生报名成功：报名记录 ID={}", courseEnroll.getId());
    }

    @Override
    public CourseDetailVO getCourseDetail(Long studentId, Long courseId) {
        Course course = getById(courseId);
        // 后续逻辑根据实际业务补充
        return null;
    }
}

通过上述流程，可以快速构建出具备基本业务逻辑的系统框架。开发者只需关注核心业务规则的调整，无需重复编写样板代码，从而大幅提升开发效率。