搜索并展示文章列表

业务逻辑:

判断分页参数设置默认值
根据分页参数构建Page列表
它这个前端有bug 只要一直往下划分页一直 + 1 没有限制所以我们若是结果为空则直接返回
文章列表不单单只显示文章还有显示发布文章的作者信息
根据查询到的文章列表中的作者id 远程调用获取用户信息
新建分页对象将用户信息和文章拼接返回

controller

若分页参数为空这设置默认值

        // 0. 判断分页参数是否存在 若不存在 设置一个默认值
        if (page == null) {
            page = 0;
        }

        if (pageSize == null) {
            pageSize = 10;
        }

根据前端传入的参数分页查询文章列表若结果为空直接返回


        PageGridResult pageGridResult = portalService.queryListPageByCondition(keyword, category, page, pageSize);

        // 分页查询结果为空则直接返回
        if (pageGridResult.getRows().size() == 0) {
            return GraceJSONResult.ok(pageGridResult);
        }

这一陀shirt一样的代码逻辑:

因为set是不可以保存重复数据的将作者id保存直set中
将set转换为json数据发起远程调用
循环之前查出的所有文章若文章的作者id相同则构建indexArticleBO并保存至list
最后将list返回

    @NotNull
    private List<IndexArticleBO> getIndexArticleList(PageGridResult pageGridResult) {

        List<Article> pageGridResultRows = (List<Article>) pageGridResult.getRows();

        Set<String> userIdSet = new HashSet<>();

        List<String> articleIdList = new ArrayList<>();

        // 获取文章所对应而id 保存之set中 用于查询用户信息
        pageGridResultRows.forEach((article -> {
            userIdSet.add(article.getPublishUserId());
            articleIdList.add(REDIS_READ_ARTICLE_COUNT + ":" + article.getId());
        }));

        String userIdsJson = JsonUtil.objectForJson(userIdSet);

        // 根据article id类别获取阅读数 若为空 则list中保存的值为空 根据articleIdList自上而下保存之readCountList中 后面根据id列表遍历 获取
        // 若为空 则没人阅读 设置为空即可
        List<String> articleReadCountList = redisOperator.mget(articleIdList);

        // restTemplate原创调用根据id列表查询用户信息
        String url = "http://admin.imoocnews.com:8003/user/queryUserListByUserIds?userIds=" + userIdsJson;
        GraceJSONResult basicUserInformationJsonResult = restTemplate.getForObject(url, GraceJSONResult.class);

        if (basicUserInformationJsonResult == null) {
            GraceException.display(ResponseStatusEnum.USER_NOT_EXIST_ERROR);
        }

        Object data = basicUserInformationJsonResult.getData();
        List<PublishUserVO> publishUserVOS = null;
        try {
            publishUserVOS = objectMapper.readValue(objectMapper.writeValueAsString(data), TypeFactory.defaultInstance().constructCollectionType(List.class, PublishUserVO.class));
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }

        if (publishUserVOS == null) {
            GraceException.display(ResponseStatusEnum.ARTICLE_QUERY_PARAMS_ERROR);
        }


        List<IndexArticleBO> indexArticleBOS = new ArrayList<>();

        // 构建主页每条文章分页信息 若userId == publishId直接设置
        for (int i = 0; i < pageGridResultRows.size(); i++) {
            IndexArticleBO indexArticleBO = new IndexArticleBO();
            BeanUtils.copyProperties(pageGridResultRows.get(i), indexArticleBO);

            for (PublishUserVO publishUserVO : publishUserVOS) {
                if (publishUserVO.getId().equalsIgnoreCase(indexArticleBO.getPublishUserId())) {
                    indexArticleBO.setPublisherVO(publishUserVO);
                    if (StringUtils.isBlank(articleReadCountList.get(i))) {
                        indexArticleBO.setReadCounts(0);
                    } else {
                        indexArticleBO.setReadCounts(Integer.valueOf(articleReadCountList.get(i)));
                    }
                }
            }

            indexArticleBOS.add(indexArticleBO);
        }

        return indexArticleBOS;
    }

最后controller直接返回indxAricleBO即可

service

判断参数非空然后拼接上去即可然后根据发文时间进行排序

 public PageGridResult queryListPageByCondition(String keyword, Integer category, Integer page, Integer pageSize) {
        QueryWrapper<Article> queryWrapper = new QueryWrapper<>();

        if (keyword != null) {
            queryWrapper.like("title", keyword);
        }

        if (category != null) {
            queryWrapper.eq("category_id", category);
        }

        setCommonQueryMapper(queryWrapper);

        queryWrapper.orderByDesc("publish_time");

        Page<Article> articlePage = new Page<>(page, pageSize);
        articleMapper.selectPage(articlePage, queryWrapper);


        return setPageGridResult(articlePage);
    }

远程调用业务逻辑

很简单遍历id列表根据id查询返回

  public GraceJSONResult queryUserListByUserIds(String userIds) {
        if (StringUtils.isBlank(userIds)) {
            GraceException.display(ResponseStatusEnum.USER_STATUS_ERROR);
        }

        List<String> userIdList = null;
        try {
            userIdList = objectMapper.readValue(userIds, TypeFactory.defaultInstance().constructCollectionType(List.class, String.class));
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }


        if (userIdList == null || userIdList.size() <= 0) {
            GraceException.display(ResponseStatusEnum.USER_STATUS_ERROR);
        }

        List<AccountBasicInfoVO> appUsers = new ArrayList<>();

        userIdList.forEach((userId) -> {
            // 因为首页会被用户不停的刷新 可以将用户数据存储到redis中以减少数据库的压力
            AppUser user = getUser(userId);
            AccountBasicInfoVO accountBasicInfoVO =
                    new AccountBasicInfoVO();

            BeanUtils.copyProperties(user, accountBasicInfoVO);
            appUsers.add(accountBasicInfoVO);

        });

        return GraceJSONResult.ok(appUsers);
    }