redis实现好友关注：关注，取关，共同关注

 

 

 

package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private IUserService userService;

    private final StringRedisTemplate stringRedisTemplate;

    public FollowServiceImpl(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    @Override
    public Result follow(Long followUserId, boolean isFollow) {
        Long userId = UserHolder.getUser().getId();
        String key = "follow_" + userId;
        // 1.判断是否是关注还是取关
        if(isFollow){
            // 2.关注
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if(isSuccess){
                //存到redis
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        }else {
            // 3.取关
            boolean isSuccess = remove(new QueryWrapper<Follow>()
                    .eq("user_id", userId).eq("follow_user_id", followUserId));
            if(isSuccess) {
                //出redis移除
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }

        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        Long userId = UserHolder.getUser().getId();
        // 1.查询是否关注
        Integer count = query()
                .eq("user_id", userId)
                .eq("follow_user_id", followUserId)
                .count();
        // 2.判断
        return Result.ok(count > 0);
    }

    @Override
    public Result followCommons(Long id) {
        // 1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        String key = "follow_" + userId;
        // 2.求交集
        String key2 = "follow_" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key,key2);
        if(intersect ==null || intersect.isEmpty()){
            // 无交集
            return Result.ok(Collections.emptyList());
        }
        // 3.解析id
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());

        // 4.查询用户
        List<UserDTO> users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());


        return Result.ok(users);
    }
}

 

    @Override
    public Result saveBlog(Blog blog) {
        // 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        // 保存探店博文
        boolean isSuccess = save(blog);
        if(!isSuccess){
            return Result.fail("新增笔记失败");
        }
        // 3.查询笔记作者的所有粉丝
        List<Follow> follows = followService.query()
                .eq("follow_user_id", user.getId()).list();
        // 4.推送笔记id给粉丝
        for(Follow follow : follows){
            // 获取粉丝id
            Long userId = follow.getUserId();
            // 推送
            String key = FEED_KEY + userId;
            stringRedisTemplate.opsForZSet().add(key, blog.getId().toString(), System.currentTimeMillis());
        }


        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        Long userId = UserHolder.getUser().getId();

        // 1.查询收件箱
        String key = FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        if(typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }

        // 2.解析数据:blodId,minTime(时间戳),offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0;
        int os = 1;
        for(ZSetOperations.TypedTuple<String> tuple : typedTuples){
            //获取id
            ids.add(Long.valueOf(tuple.getValue()));
            //获取分数(时间戳)
            long time = tuple.getScore().longValue();
            if(time == minTime){
                os++;
            }else{
                minTime = time;
                os = 1;
            }

        }

        // 3.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query()
                .in("id",ids).last("ORDER BY FIELD(id,"+ idStr +")").list();

        for(Blog blog : blogs){
            // 3.1.查询blog相关的用户
            queryBlogUser(blog);
            // 3.2查询blog是否被点赞
            isBlogLiked(blog);
        }

        // 4.封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);
        return Result.ok(r);
    }