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

技术细节

1.Controller层

@GetMapping("/page")
    @ApiOperation("分页查询问题")
    public PageDTO<QuestionVO> queryQuestionPage(QuestionPageQuery query){
        return questionService.queryQuestionPage(query);
    }

2.Service层:

@Override
    public PageDTO<QuestionVO> queryQuestionPage(QuestionPageQuery query) {
        //1.参数校验courseId
        if (query.getCourseId() == null){
            throw new BadRequestException("课程id为空");
        }
        //2.获取用户id
        Long userId = UserContext.getUser();
        //3.分页查询互动问题interaction_question 条件:courseId, onlyMine(非必需,出现则传userId), sectionId(非必需), hidden=false,顺序按提问时间倒序
        Page<InteractionQuestion> page = this.lambdaQuery()
                //指定不查的字段
                .select(InteractionQuestion.class, tableFieldInfo -> !tableFieldInfo.getProperty().equals("description"))
                .eq(InteractionQuestion::getCourseId, query.getCourseId())
                .eq(query.getOnlyMine() != null, InteractionQuestion::getUserId, userId)
                .eq(query.getSectionId() != null, InteractionQuestion::getSectionId, query.getSectionId())
                .eq(InteractionQuestion::getHidden, false)
                .page(query.toMpPage("create.time", true));
        List<InteractionQuestion> records = page.getRecords();
        if (CollUtils.isEmpty(records)){
            return PageDTO.empty(page);
        }
        //4.根据最新回答id,批量查询问答信息
        //4.1获取到最新回答的id
        Set<Long> latestAnswerIdSet = new HashSet<>();
        //5.1
        Set<Long> userIdSet = records.stream().map(InteractionQuestion::getUserId).collect(Collectors.toSet());
        for (InteractionQuestion question : records) {
            if (!question.getAnonymity()) {//只获取非匿名的用户id
                userIdSet.add(question.getUserId());
            }
            if (question.getLatestAnswerId() != null) {
                latestAnswerIdSet.add(question.getLatestAnswerId());
            }
        }
        //4.2调用回答服务批量查询回答信息,如果被hidden则不显示
        Map<Long, InteractionReply> replyMap = new HashMap<>();
        if (CollUtils.isNotEmpty(latestAnswerIdSet)){
            //List<InteractionReply> replyList = replyService.listByIds(latestAnswerIdSet);
            List<InteractionReply> replyList = replyService.list(Wrappers.<InteractionReply>lambdaQuery()
                    .in(InteractionReply::getId, latestAnswerIdSet)
                    .eq(InteractionReply::getHidden, false));
            for (InteractionReply reply : replyList) {
                if (!reply.getAnonymity()) {
                    userIdSet.add(reply.getUserId());//将最新回答的用户id存入用户id集合
                }
                replyMap.put(reply.getId(), reply);
            }
        }
        //5.远程调用用户服务,获取用户信息 批量
        //5.1获取用户id集合
        List<UserDTO> userDTOS = userClient.queryUserByIds(userIdSet);
        Map<Long, UserDTO> userMap = userDTOS.stream().collect(Collectors.toMap(UserDTO::getId, c -> c));
        //6.封装vo返回
        ArrayList<QuestionVO> voList = new ArrayList<>();
        for (InteractionQuestion record : records) {
            QuestionVO vo = BeanUtils.copyBean(record, QuestionVO.class);

            if (!vo.getAnonymity()) {
                UserDTO userDTO = userMap.get(record.getUserId());
                if (userDTO != null) {
                    vo.setUserName(userDTO.getName());
                    vo.setUserIcon(userDTO.getIcon());
                }
            }
            InteractionReply reply = replyMap.get(record.getLatestAnswerId());
            if (reply != null){
                vo.setLatestReplyContent(reply.getContent());
                if (!reply.getAnonymity()){
                    UserDTO userDTO = userMap.get(record.getUserId());
                    if (userDTO != null){
                        vo.setLatestReplyUser(userDTO.getName());
                    }

                }
            }
            voList.add(vo);
        }
        return PageDTO.of(page, voList);
    }

3.Mapper层

效果展示