feat(comment): 引入本地缓存优化评论查询性能

- 添加 Caffeine 依赖以支持本地缓存
- 实现评论详情的本地缓存机制，减少 Redis 查询压力
-优化分页查询逻辑，优先从本地缓存获取评论数据
- 异步同步评论详情至本地缓存，提升响应速度
- 简化 Redis 操作代码，提高可读性和维护性

han-note-comment/han-note-comment-biz/pom.xml

@@ -130,6 +130,12 @@
             <artifactId>han-note-user-api</artifactId>
         </dependency>
 
+        <!-- Caffeine 本地缓存 -->
+        <dependency>
+            <groupId>com.github.ben-manes.caffeine</groupId>
+            <artifactId>caffeine</artifactId>
+        </dependency>
+
 
     </dependencies>
 

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

@@ -3,6 +3,8 @@ package com.hanserwei.hannote.comment.biz.service.impl;
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.util.RandomUtil;
 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
+import com.github.benmanes.caffeine.cache.Cache;
+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;
@@ -34,7 +36,11 @@ import com.hanserwei.hannote.user.dto.resp.FindUserByIdRspDTO;
 import jakarta.annotation.Resource;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.StringUtils;
-import org.springframework.data.redis.core.*;
+import org.apache.logging.log4j.util.Strings;
+import org.jspecify.annotations.NonNull;
+import org.springframework.data.redis.core.RedisCallback;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.core.ZSetOperations;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 import org.springframework.stereotype.Service;
 
@@ -64,6 +70,15 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
     @Resource(name = "taskExecutor")
     private ThreadPoolTaskExecutor threadPoolTaskExecutor;
 
+    /**
+     * 评论详情本地缓存
+     */
+    private static final Cache<Long, String> LOCAL_CACHE = Caffeine.newBuilder()
+            .initialCapacity(10000) // 设置初始容量为 10000 个条目
+            .maximumSize(10000) // 设置缓存的最大容量为 10000 个条目
+            .expireAfterWrite(1, TimeUnit.HOURS) // 设置缓存条目在写入后 1 小时过期
+            .build();
+
     @Override
     public Response<?> publishComment(PublishCommentReqVO publishCommentReqVO) {
         // 评论正文
@@ -167,10 +182,8 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
         }
 
         // 分页返回参数
-        List<FindCommentItemRspVO> commentRspVOS = null;
+        List<FindCommentItemRspVO> commentRspVOS;
 
-        // 若评论总数大于0
-        if (count > 0) {
         commentRspVOS = Lists.newArrayList();
         // 计算分页查询的offset
         long offset = PageResponse.getOffset(pageNo, pageSize);
@@ -198,8 +211,45 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
                 // Set 转 List
                 List<Object> commentIdList = Lists.newArrayList(commentIds);
 
+                // 先查询本地缓存
+                // 新建一个集合用于存储本地缓存中不存在的评论ID
+                List<Long> localeCacheExpiredCommentIds = Lists.newArrayList();
+
+                // 构建本地缓存的key集合
+                List<Long> localCacheKeys = commentIdList.stream()
+                        .map(e -> Long.valueOf(e.toString()))
+                        .toList();
+
+                // 批量查询本地缓存
+                Map<Long, @NonNull String> commentIdAndDetailJsonMap = LOCAL_CACHE.getAll(localCacheKeys, missingKeys -> {
+                    // 对应本地缓存缺失的Key返回空字符串
+                    Map<Long, String> missingData = Maps.newHashMap();
+                    missingKeys.forEach(key -> {
+                        // 记录缓存中不存在的ID
+                        localeCacheExpiredCommentIds.add(key);
+                        // 不存在的评论详情，对其Value设置为空字符串
+                        missingData.put(key, Strings.EMPTY);
+                    });
+                    return missingData;
+                });
+
+                // 如果localCacheExpiredCommentIds的大小不等于commentIdList的大小，说明本地缓存中有数据
+                if (CollUtil.size(localeCacheExpiredCommentIds) != commentIdList.size()) {
+                    // 将本地缓存中的评论详情Json转为实体类添加到VO返参集合中
+                    for (String value : commentIdAndDetailJsonMap.values()) {
+                        if (StringUtils.isBlank(value)) continue;
+                        FindCommentItemRspVO commentRspVO = JsonUtils.parseObject(value, FindCommentItemRspVO.class);
+                        commentRspVOS.add(commentRspVO);
+                    }
+                }
+
+                // 如果localCacheExpiredCommentIds大小为0，说明评论详情全在本地缓存中，直接响应返参
+                if (CollUtil.size(localeCacheExpiredCommentIds) == 0) {
+                    return PageResponse.success(commentRspVOS, pageNo, count, pageSize);
+                }
+
                 // 构建 MGET 批量查询评论详情的 Key 集合
-                    List<String> commentIdKeys = commentIdList.stream()
+                List<String> commentIdKeys = localeCacheExpiredCommentIds.stream()
                         .map(RedisKeyConstants::buildCommentDetailKey)
                         .toList();
 
@@ -208,6 +258,7 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
 
                 // 可能存在部分评论不在缓存中，已经过期被删除，这些评论 ID 需要提取出来，等会查数据库
                 List<Long> expiredCommentIds = Lists.newArrayList();
+                if (commentsJsonList != null) {
                     for (int i = 0; i < commentsJsonList.size(); i++) {
                         String commentJson = (String) commentsJsonList.get(i);
                         if (Objects.nonNull(commentJson)) {
@@ -219,6 +270,7 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
                             expiredCommentIds.add(Long.valueOf(commentIdList.get(i).toString()));
                         }
                     }
+                }
 
                 // 对于不存在的一级评论，需要批量从数据库中查询，并添加到 commentRspVOS 中
                 if (CollUtil.isNotEmpty(expiredCommentIds)) {
@@ -232,16 +284,42 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
                     .sorted(Comparator.comparing(FindCommentItemRspVO::getHeat).reversed())
                     .collect(Collectors.toList());
 
+            // 异步将评论详情，同步到本地缓存
+            syncCommentDetail2LocalCache(commentRspVOS);
+
             return PageResponse.success(commentRspVOS, pageNo, count, pageSize);
         }
         // 缓存中没有，则查询数据库
         //查询一级评论
         List<CommentDO> oneLevelCommentIds = commentDOMapper.selectPageList(noteId, offset, pageSize);
         getCommentDataAndSync2Redis(oneLevelCommentIds, noteId, commentRspVOS);
-        }
+
+        // 异步将评论详情，同步到本地缓存
+        syncCommentDetail2LocalCache(commentRspVOS);
+
         return PageResponse.success(commentRspVOS, pageNo, count, pageSize);
     }
 
+    /**
+     * 同步评论详情到本地缓存中
+     *
+     * @param commentRspVOS 评论VO列表
+     */
+    private void syncCommentDetail2LocalCache(List<FindCommentItemRspVO> commentRspVOS) {
+        // 开启一个异步线程
+        threadPoolTaskExecutor.execute(() -> {
+            // 构建缓存所需的键值
+            Map<Long, String> localCacheData = Maps.newHashMap();
+            commentRspVOS.forEach(commentRspVO -> {
+                Long commentId = commentRspVO.getCommentId();
+                localCacheData.put(commentId, JsonUtils.toJsonString(commentRspVO));
+            });
+
+            // 批量写入本地缓存
+            LOCAL_CACHE.putAll(localCacheData);
+        });
+    }
+
     /**
      * 获取一级评论数据，并同步到 Redis 中
      *
@@ -378,10 +456,10 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
 
 
                     // 批量写入并设置过期时间
-                    connection.setEx(
+                    connection.stringCommands().setEx(
-                            redisTemplate.getStringSerializer().serialize(entry.getKey()),
+                            Objects.requireNonNull(redisTemplate.getStringSerializer().serialize(entry.getKey())),
                             randomExpire,
-                            redisTemplate.getStringSerializer().serialize(jsonStr)
+                            Objects.requireNonNull(redisTemplate.getStringSerializer().serialize(jsonStr))
                     );
                 }
                 return null;
@@ -396,18 +474,12 @@ public class CommentServiceImpl extends ServiceImpl<CommentDOMapper, CommentDO>
      * @param dbCount             数据库查询到的笔记评论总数
      */
     private void syncNoteCommentTotal2Redis(String noteCommentTotalKey, Long dbCount) {
-        redisTemplate.executePipelined(new SessionCallback<>() {
-            @Override
-            public Object execute(RedisOperations operations) {
         // 同步 hash 数据
-                operations.opsForHash().put(noteCommentTotalKey, RedisKeyConstants.FIELD_COMMENT_TOTAL, dbCount);
+        redisTemplate.opsForHash().put(noteCommentTotalKey, RedisKeyConstants.FIELD_COMMENT_TOTAL, dbCount);
 
         // 随机过期时间 (保底1小时 + 随机时间)，单位：秒
         long expireTime = 60 * 60 + RandomUtil.randomInt(4 * 60 * 60);
-                operations.expire(noteCommentTotalKey, expireTime, TimeUnit.SECONDS);
+        redisTemplate.expire(noteCommentTotalKey, expireTime, TimeUnit.SECONDS);
-                return null;
-            }
-        });
     }
 
     /**