查询我正在学习的课程

文章目录

• • 概要
  • 整体架构流程
  • 技术细节
  • 小结

概要

需求分析以及接口设计

可以看到返回值结果与分页查询的课表VO基本类似，因此这里可以复用LearningLessonVO实体，但是需要添加几个字段：

• courseAmount

• latestSectionName

• latestSectionIndex

  其中CataSimpleInfoDTO中就包含了章节信息：

  @Data public class CataSimpleInfoDTO { @ApiModelProperty("目录id") private Long id; @ApiModelProperty("目录名称") private String name; @ApiModelProperty("数字序号，不包含章序号") private Integer cIndex; }

技术细节

1.Controller层

@ApiOperation("查询我正在学习的课程")
    @GetMapping("/now")
    public LearningLessonVO queryMyCurrentLesson(){
        return iLearningLessonService.queryMyCurrentLesson();
    }

2.Service层:

public LearningLessonVO queryMyCurrentLesson() {
        //1.获取到用户id
        Long userId = UserContext.getUser();
        //2.查询最近一次的学习课程信息(根据userid,status = 1,latest_learn_time倒序排序即可得出)
        LearningLesson lesson = this.lambdaQuery()
                .eq(LearningLesson::getUserId, userId)
                .eq(LearningLesson::getStatus, LessonStatus.LEARNING)
                .orderByDesc(LearningLesson::getLatestLearnTime)
                .last("limit 1")
                .one();
        //3.填充vo
        LearningLessonVO vo = new LearningLessonVO();
        vo.setCourseId(lesson.getCourseId());
        vo.setCreateTime(lesson.getCreateTime());
        vo.setExpireTime(lesson.getExpireTime());
        vo.setLearnedSections(lesson.getLearnedSections());
        //远程调用course服务
        CourseFullInfoDTO courseFullInfoDTO = courseClient.getCourseInfoById(lesson.getCourseId(), false, false);
        vo.setSections(courseFullInfoDTO.getSectionNum());
        vo.setCourseName(courseFullInfoDTO.getName());
        Integer courseAmount = Math.toIntExact(this.lambdaQuery()
                .eq(LearningLesson::getUserId, userId)
                .count());
        vo.setCourseAmount(courseAmount);
        //远程调用catalogue服务
        List<Long> latestSectionId = List.of(lesson.getLatestSectionId());
        List<CataSimpleInfoDTO> cataSimpleInfoDTOList = catalogueClient.batchQueryCatalogue(latestSectionId);
        CataSimpleInfoDTO cataSimpleInfoDTO = cataSimpleInfoDTOList.get(0);
        vo.setLatestSectionName(cataSimpleInfoDTO.getName());
        vo.setLatestSectionIndex(cataSimpleInfoDTO.getCIndex());
        //4.返回vo
        return vo;
    }

3.Mapper层

效果展示