feat(comment): 实现二级评论分页查询功能

- 新增子评论分页查询接口 /comment/child/list- 添加查询一级评论下子评论总数的 Mapper 方法
- 实现二级评论分页数据查询的 Mapper 方法
- 补充对应的 XML 查询语句，支持按 parent_id 查询子评论
- 创建 FindChildCommentItemRspVO 和 FindChildCommentPageListReqVO VO 类
- 在 CommentServiceImpl 中实现子评论分页查询业务逻辑
- 支持批量查询子评论内容及用户信息并组装返回数据
- 添加 HTTP 客户端测试用例用于验证接口功能

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/controller/CommentController.java

@@ -3,9 +3,7 @@ package com.hanserwei.hannote.comment.biz.controller;
 import com.hanserwei.framework.biz.operationlog.aspect.ApiOperationLog;
 import com.hanserwei.framework.common.response.PageResponse;
 import com.hanserwei.framework.common.response.Response;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentItemRspVO;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentPageListReqVO;
-import com.hanserwei.hannote.comment.biz.model.vo.PublishCommentReqVO;
+import com.hanserwei.hannote.comment.biz.model.vo.*;
 import com.hanserwei.hannote.comment.biz.service.CommentService;
 import jakarta.annotation.Resource;
 import lombok.extern.slf4j.Slf4j;
@@ -35,4 +33,10 @@ public class CommentController {
         return commentService.findCommentPageList(findCommentPageListReqVO);
     }
 
+    @PostMapping("/child/list")
+    @ApiOperationLog(description = "二级评论分页查询")
+    public PageResponse<FindChildCommentItemRspVO> findChildCommentPageList(@Validated @RequestBody FindChildCommentPageListReqVO findChildCommentPageListReqVO) {
+        return commentService.findChildCommentPageList(findChildCommentPageListReqVO);
+    }
+
 }

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/domain/mapper/CommentDOMapper.java

@@ -82,4 +82,24 @@ public interface CommentDOMapper extends BaseMapper<CommentDO> {
      * @return 热门评论
      */
     List<CommentDO> selectHeatComments(Long noteId);
+
+    /**
+     * 查询一级评论下子评论总数
+     *
+     * @param commentId 一级评论 ID
+     * @return 一级评论下子评论总数
+     */
+    Long selectChildCommentTotalById(Long commentId);
+
+    /**
+     * 查询二级评论分页数据
+     *
+     * @param parentId 一级评论 ID
+     * @param offset   偏移量
+     * @param pageSize 页大小
+     * @return 二级评论分页数据
+     */
+    List<CommentDO> selectChildPageList(@Param("parentId") Long parentId,
+                                        @Param("offset") long offset,
+                                        @Param("pageSize") long pageSize);
 }

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/model/vo/FindChildCommentItemRspVO.java

@@ -0,0 +1,63 @@
+package com.hanserwei.hannote.comment.biz.model.vo;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class FindChildCommentItemRspVO {
+
+    /**
+     * 评论 ID
+     */
+    private Long commentId;
+
+    /**
+     * 发布者用户 ID
+     */
+    private Long userId;
+
+    /**
+     * 头像
+     */
+    private String avatar;
+
+    /**
+     * 昵称
+     */
+    private String nickname;
+
+    /**
+     * 评论内容
+     */
+    private String content;
+
+    /**
+     * 评论内容
+     */
+    private String imageUrl;
+
+    /**
+     * 发布时间
+     */
+    private String createTime;
+
+    /**
+     * 被点赞数
+     */
+    private Long likeTotal;
+
+    /**
+     * 回复的用户昵称
+     */
+    private String replyUserName;
+
+    /**
+     * 回复的用户 ID
+     */
+    private Long replyUserId;
+}

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/model/vo/FindChildCommentPageListReqVO.java

@@ -0,0 +1,20 @@
+package com.hanserwei.hannote.comment.biz.model.vo;
+
+import jakarta.validation.constraints.NotNull;
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class FindChildCommentPageListReqVO {
+
+    @NotNull(message = "父评论 ID 不能为空")
+    private Long parentCommentId;
+
+    @NotNull(message = "页码不能为空")
+    private Integer pageNo = 1;
+}

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/service/CommentService.java

@@ -4,9 +4,7 @@ import com.baomidou.mybatisplus.extension.service.IService;
 import com.hanserwei.framework.common.response.PageResponse;
 import com.hanserwei.framework.common.response.Response;
 import com.hanserwei.hannote.comment.biz.domain.dataobject.CommentDO;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentItemRspVO;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentPageListReqVO;
-import com.hanserwei.hannote.comment.biz.model.vo.PublishCommentReqVO;
+import com.hanserwei.hannote.comment.biz.model.vo.*;
 
 public interface CommentService extends IService<CommentDO> {
     /**
@@ -24,4 +22,12 @@ public interface CommentService extends IService<CommentDO> {
      * @return 响应
      */
     PageResponse<FindCommentItemRspVO> findCommentPageList(FindCommentPageListReqVO findCommentPageListReqVO);
+
+    /**
+     * 二级评论分页查询
+     *
+     * @param findChildCommentPageListReqVO 二级评论分页查询参数
+     * @return 响应
+     */
+    PageResponse<FindChildCommentItemRspVO> findChildCommentPageList(FindChildCommentPageListReqVO findChildCommentPageListReqVO);
 }

han-note-comment/han-note-comment-biz/src/main/java/com/hanserwei/hannote/comment/biz/service/impl/CommentServiceImpl.java

@@ -8,6 +8,7 @@ import com.github.benmanes.caffeine.cache.Caffeine;
 import com.google.common.base.Preconditions;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
+import com.google.common.collect.Sets;
 import com.hanserwei.framework.biz.context.holder.LoginUserContextHolder;
 import com.hanserwei.framework.common.constant.DateConstants;
 import com.hanserwei.framework.common.exception.ApiException;
@@ -22,9 +23,7 @@ import com.hanserwei.hannote.comment.biz.domain.mapper.CommentDOMapper;
 import com.hanserwei.hannote.comment.biz.domain.mapper.NoteCountDOMapper;
 import com.hanserwei.hannote.comment.biz.enums.ResponseCodeEnum;
 import com.hanserwei.hannote.comment.biz.model.dto.PublishCommentMqDTO;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentItemRspVO;
-import com.hanserwei.hannote.comment.biz.model.vo.FindCommentPageListReqVO;
-import com.hanserwei.hannote.comment.biz.model.vo.PublishCommentReqVO;
+import com.hanserwei.hannote.comment.biz.model.vo.*;
 import com.hanserwei.hannote.comment.biz.retry.SendMqRetryHelper;
 import com.hanserwei.hannote.comment.biz.rpc.DistributedIdGeneratorRpcService;
 import com.hanserwei.hannote.comment.biz.rpc.KeyValueRpcService;
@@ -300,6 +299,133 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
         return PageResponse.success(commentRspVOS, pageNo, count, pageSize);
     }
 
+    @Override
+    public PageResponse<FindChildCommentItemRspVO> findChildCommentPageList(FindChildCommentPageListReqVO findChildCommentPageListReqVO) {
+        // 父评论 ID
+        Long parentCommentId = findChildCommentPageListReqVO.getParentCommentId();
+        // 当前页码
+        Integer pageNo = findChildCommentPageListReqVO.getPageNo();
+        // 每页展示的二级评论数 (小红书 APP 中是一次查询 6 条)
+        long pageSize = 6;
+
+        // TODO：先从缓存中查询，待完善
+
+        // 查询一级评论下的子评论数目
+        Long count = commentDOMapper.selectChildCommentTotalById(parentCommentId);
+
+        // 若一级评论不存在或者评论数目为0，则直接返回
+        if (Objects.isNull(count) || count == 0) {
+            return PageResponse.success(null, pageNo, 0);
+        }
+
+        // 分页返回参数VO
+        List<FindChildCommentItemRspVO> childCommentRspVOS = Lists.newArrayList();
+
+        // 计算分页查询的偏移量offset（需要加1，因为最早回复的二级评论已经被展示了）
+        long offset = PageResponse.getOffset(pageNo, pageSize) + 1;
+
+        // 分页查询子评论
+        List<CommentDO> childCommentDOS = commentDOMapper.selectChildPageList(parentCommentId, offset, pageSize);
+
+        // 调用KV服务需要的入参
+        List<FindCommentContentReqDTO> findCommentContentReqDTOS = Lists.newArrayList();
+        // 调用用户服务需要的入参
+        Set<Long> userIds = Sets.newHashSet();
+
+        // 归属的笔记ID
+        Long noteId = null;
+
+        // 循环提取RPC调用所需要的入参数据
+        for (CommentDO childCommentDO : childCommentDOS) {
+            noteId = childCommentDO.getNoteId();
+            // 构建调用KV服务批量查询评论内容的入参
+            Boolean isContentEmpty = childCommentDO.getIsContentEmpty();
+            if (!isContentEmpty) {
+                FindCommentContentReqDTO findCommentContentReqDTO = FindCommentContentReqDTO.builder()
+                        .contentId(childCommentDO.getContentUuid())
+                        .yearMonth(DateConstants.DATE_FORMAT_Y_M.format(childCommentDO.getCreateTime()))
+                        .build();
+                findCommentContentReqDTOS.add(findCommentContentReqDTO);
+            }
+            // 构建调用用户服务批量查询用户信息入参
+            userIds.add(childCommentDO.getUserId());
+
+            Long parentId = childCommentDO.getParentId();
+            Long replyCommentId = childCommentDO.getReplyCommentId();
+            // 若当前评论的 replyCommentId 不等于 parentId，则前端需要展示回复的哪个用户，如  “回复 Hanserwei：”
+            if (!Objects.equals(parentId, replyCommentId)) {
+                userIds.add(childCommentDO.getReplyUserId());
+            }
+        }
+
+        // RPC 调用KV服务批量查询评论内容
+        List<FindCommentContentRspDTO> findCommentContentRspDTOS = keyValueRpcService.batchFindCommentContent(noteId, findCommentContentReqDTOS);
+
+        // DTO转Map方便后续拼接数据
+        Map<String, String> commentUuidAndContentMap = null;
+        if (CollUtil.isNotEmpty(findCommentContentRspDTOS)) {
+            commentUuidAndContentMap = findCommentContentRspDTOS.stream()
+                    .collect(Collectors.toMap(FindCommentContentRspDTO::getContentId, FindCommentContentRspDTO::getContent));
+        }
+
+        // RPC 调用用户服务批量查询用户信息
+        List<FindUserByIdRspDTO> findUserByIdRspDTOS = userRpcService.findByIds(userIds.stream().toList());
+
+        // DTO转Map方便后续拼接数据
+        Map<Long, FindUserByIdRspDTO> userIdAndDTOMap = null;
+        if (CollUtil.isNotEmpty(findUserByIdRspDTOS)) {
+            userIdAndDTOMap = findUserByIdRspDTOS.stream()
+                    .collect(Collectors.toMap(FindUserByIdRspDTO::getId, e -> e));
+        }
+
+        // DO 转 VO
+        for (CommentDO childCommentDO : childCommentDOS) {
+            // 构建 VO 实体类
+            Long userId = childCommentDO.getUserId();
+            FindChildCommentItemRspVO childCommentRspVO = FindChildCommentItemRspVO.builder()
+                    .userId(userId)
+                    .commentId(childCommentDO.getId())
+                    .imageUrl(childCommentDO.getImageUrl())
+                    .createTime(DateUtils.formatRelativeTime(childCommentDO.getCreateTime()))
+                    .likeTotal(childCommentDO.getLikeTotal())
+                    .build();
+
+            // 填充用户信息(包括评论发布者、回复的用户)
+            if (CollUtil.isNotEmpty(userIdAndDTOMap)) {
+                FindUserByIdRspDTO findUserByIdRspDTO = userIdAndDTOMap.get(userId);
+                // 评论发布者用户信息(头像、昵称)
+                if (Objects.nonNull(findUserByIdRspDTO)) {
+                    childCommentRspVO.setAvatar(findUserByIdRspDTO.getAvatar());
+                    childCommentRspVO.setNickname(findUserByIdRspDTO.getNickName());
+                }
+
+                // 评论回复的哪个
+                Long replyCommentId = childCommentDO.getReplyCommentId();
+                Long parentId = childCommentDO.getParentId();
+
+                if (Objects.nonNull(replyCommentId)
+                        && !Objects.equals(replyCommentId, parentId)) {
+                    Long replyUserId = childCommentDO.getReplyUserId();
+                    FindUserByIdRspDTO replyUser = userIdAndDTOMap.get(replyUserId);
+                    childCommentRspVO.setReplyUserName(replyUser.getNickName());
+                    childCommentRspVO.setReplyUserId(replyUser.getId());
+                }
+            }
+
+            // 评论内容
+            if (CollUtil.isNotEmpty(commentUuidAndContentMap)) {
+                String contentUuid = childCommentDO.getContentUuid();
+                if (StringUtils.isNotBlank(contentUuid)) {
+                    childCommentRspVO.setContent(commentUuidAndContentMap.get(contentUuid));
+                }
+            }
+
+            childCommentRspVOS.add(childCommentRspVO);
+        }
+
+        return PageResponse.success(childCommentRspVOS, pageNo, count, pageSize);
+    }
+
     /**
      * 同步评论详情到本地缓存中
      *

han-note-comment/han-note-comment-biz/src/main/resources/mapperxml/CommentDOMapper.xml

@@ -154,4 +154,30 @@
         order by heat desc
         limit 500
     </select>
+
+    <select id="selectChildCommentTotalById" resultType="long">
+        select child_comment_total
+        from t_comment
+        where id = #{commentId}
+          and level = 1
+    </select>
+
+    <select id="selectChildPageList" resultMap="BaseResultMap" parameterType="map">
+        select id,
+               user_id,
+               note_id,
+               content_uuid,
+               is_content_empty,
+               image_url,
+               like_total,
+               create_time,
+               reply_user_id,
+               parent_id,
+               reply_comment_id
+        from t_comment
+        where parent_id = #{parentId}
+          and level = 2
+        order by id
+        limit #{offset}, #{pageSize}
+    </select>
 </mapper>