12.2_黑马Redis实战篇达人探店&好友关注

目录

实战篇03

thinking ：提取公共部分为一个方法的快捷键？

thinking：redis中的ismember？

thinking:BooleanUtil.isTrue?

实战篇04

thinking：zscore的用法？

thinking：stream().map().collect?

thinking：引用静态方法？JAVA中的双冒号？ 

thinking：StringUtils.join的用法？

thinking:StrUtil.join（）?

实战篇05

实战篇06

thinking：在redis中求交集？  用inersect。

实战篇07

实战篇08

thinking:System.currentTimeMillis()？

​编辑 thinking：时间戳？​编辑

实战篇09

实战篇10

​编辑 thinking：JAVA中的long和int有什么区别？

thinking：为什么long类型的变量需要加上L?float类型的变量要加上F？

---

实战篇03

thinking ：提取公共部分为一个方法的快捷键？

ctrl + alt + m

thinking：redis中的ismember？

redis五大集合之一（Set集合常用命令）_redis set ismember-CSDN博客

可以简化为：

thinking:BooleanUtil.isTrue?

hutool工具包快速入门_beanutil.fillbeanwithmap-CSDN博客

package com.hmdp.service.impl;

import cn.hutool.core.util.BooleanUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlockLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        //1. 查询blog
        Blog blog  =getById(id);
        if(blog == null){
            return Result.fail("笔记不存在！");
        }
        //2. 查询blog有关的用户
        queryBlogUser(blog);
        //3.查询blog是否被点赞
        isBlockLiked(blog);
        return Result.ok(blog);
    }

    private void isBlockLiked(Blog blog) {
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key ="blog:liked:"+blog.getId();
        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        blog.setIsLike(BooleanUtil.isTrue(isMember));

    }

    @Override
    public Result likeBlog(Long id) {
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key ="blog:liked:"+id;
        Boolean isMember = stringRedisTemplate.opsForSet().isMember(key, userId.toString());
        if(BooleanUtil.isFalse(isMember)) {
            //3.如果未点赞，可以点赞
            //3.1数据库点赞数 +1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2保存用户到Redis的set集合
            if (isSuccess) {
                stringRedisTemplate.opsForSet().add(key, userId.toString());
            }
        }else {
            //4如果已点赞，取消点赞
            //4.1数据库点赞数 -1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //4.2把用户从Redis的set集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}

实战篇04

thinking：zscore的用法？

Redis zrangebylex的使用 | Redis sorted_set不可不知的秘密_血煞长虹的博客-CSDN博客

thinking：stream().map().collect?

thinking：引用静态方法？JAVA中的双冒号？ 

当时看黑马上下部的时候一直没有搞懂的内容之一。现在来恶补一下。

方法引用-02-引用静态方法_哔哩哔哩_bilibili

 

 

 

接着判断它是否符合以下三个要求

接着，我们来看看视频中的例子

Java中Long::valueOf是什么意思_long.valueof-CSDN博客

 有几篇讲JAVA双冒号的文章也挺好的，可以看看。

深入理解Java双冒号(::)运算符的使用（*）_java 双冒号_Firm陈的博客-CSDN博客

Java 中的双冒号“::”_java ::_JFS_Study的博客-CSDN博客  

 发现很多知识点当时很难理解，一段时间之后就突然开窍。

遂决定明年暑假前把JAVA基础篇再二刷一遍。

thinking：StringUtils.join的用法？

StringUtils.join的用法_stringutils.join用法-CSDN博客

thinking:StrUtil.join（）?

Hutool Java开发工具包_strutil.join-CSDN博客

 Hutool，轻松玩转字符串操作, 都是案例，值得收藏！_hutool 字符串拼接-CSDN博客

package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
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;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlockLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        //1. 查询blog
        Blog blog  =getById(id);
        if(blog == null){
            return Result.fail("笔记不存在！");
        }
        //2. 查询blog有关的用户
        queryBlogUser(blog);
        //3.查询blog是否被点赞
        isBlockLiked(blog);
        return Result.ok(blog);
    }

    private void isBlockLiked(Blog blog) {
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        if(user == null){
            //用户未登录，无需查询是否点赞
            return;
        }
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key ="blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);

    }

    @Override
    public Result likeBlog(Long id) {
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key =BLOG_LIKED_KEY+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null) {
            //3.如果未点赞，可以点赞
            //3.1数据库点赞数 +1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2保存用户到Redis的set集合
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(),System.currentTimeMillis());
            }
        }else {
            //4如果已点赞，取消点赞
            //4.1数据库点赞数 -1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //4.2把用户从Redis的set集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key =BLOG_LIKED_KEY + id;
        //1.查询top5的点赞用户 zrange key 0 4
        Set top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5 ==null || top5.isEmpty()){
            return  Result.ok(Collections.emptyList());
        }
        //2.解析出其中的用户id
        List ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        //3.根据用户id查询用户
        List userDTOS = userService.query()
                .in("id",ids)
                .last("ORDER BY FIELD(id,"+idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4.返回
        return Result.ok(userDTOS);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}

实战篇05

package com.hmdp.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.hmdp.dto.Result;
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.utils.UserHolder;
import org.springframework.stereotype.Service;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl implements IFollowService {

    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        //1.判断到底是关注还是取关
        if(isFollow){
            //2.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            save(follow);
        }
        else{
            //3.取关，删除
            remove(new QueryWrapper()
                    .eq("user_id",userId)
                    .eq("follow_user_id",followUserId));
        }
        return Result.ok();
    }

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

实战篇06

thinking：在redis中求交集？  用inersect。

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.CacheClient;
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;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl implements IFollowService {
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IUserService userService;
    @Override
    public Result follow(Long followUserId, Boolean isFollow) {
        //1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        String key ="follows:" + userId;
        //1.判断到底是关注还是取关
        if(isFollow){
            //2.关注，新增数据
            Follow follow = new Follow();
            follow.setUserId(userId);
            follow.setFollowUserId(followUserId);
            boolean isSuccess = save(follow);
            if(isSuccess){
                //把关注用户的id，放入redis的set集合
                stringRedisTemplate.opsForSet().add(key,followUserId.toString());
            }
        } else{
            //3.取关，删除
            boolean isSuccess = remove(new QueryWrapper()
                    .eq("user_id", userId)
                    .eq("follow_user_id", followUserId));
            if (isSuccess) {
                //把关注用户的id从Redis集合中移除
                stringRedisTemplate.opsForSet().remove(key, followUserId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long followUserId) {
        //1.获取登录用户
        Long userId = UserHolder.getUser().getId();
        //2.查询是否关注
        Integer count = query().eq("user_id", userId)
                .eq("follow_user_id", followUserId).count();
        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 = "follows:"+userId;
        //2.求交集
        String key2 = "follows"+ id;
        Set intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if(intersect == null || intersect.isEmpty()){
            //无交集
            return Result.ok(Collections.emptyList());
        }
        //3.解析id集合
        List ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        //4.查询用户
        List users = userService.listByIds(ids)
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());

        return Result.ok(users);
    }
}

实战篇07

实战篇08

对于数据经常发生变化的，用sortset处理分页问题 

thinking:System.currentTimeMillis()？

System.currentTimeMillis()用法及其计算方式与时间的单位转换_Tan.]der的博客-CSDN博客

Java获取当前系统时间-CSDN博客

 thinking：时间戳？

 获取系统时间以及时间戳的理解与使用_系统时间戳-CSDN博客

package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
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;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlockLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        //1. 查询blog
        Blog blog  =getById(id);
        if(blog == null){
            return Result.fail("笔记不存在！");
        }
        //2. 查询blog有关的用户
        queryBlogUser(blog);
        //3.查询blog是否被点赞
        isBlockLiked(blog);
        return Result.ok(blog);
    }

    private void isBlockLiked(Blog blog) {
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        if(user == null){
            //用户未登录，无需查询是否点赞
            return;
        }
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key ="blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);

    }

    @Override
    public Result likeBlog(Long id) {
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key =BLOG_LIKED_KEY+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null) {
            //3.如果未点赞，可以点赞
            //3.1数据库点赞数 +1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2保存用户到Redis的set集合
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(),System.currentTimeMillis());
            }
        }else {
            //4如果已点赞，取消点赞
            //4.1数据库点赞数 -1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //4.2把用户从Redis的set集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key =BLOG_LIKED_KEY + id;
        //1.查询top5的点赞用户 zrange key 0 4
        Set top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5 ==null || top5.isEmpty()){
            return  Result.ok(Collections.emptyList());
        }
        //2.解析出其中的用户id
        List ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        //3.根据用户id查询用户
        List userDTOS = userService.query()
                .in("id",ids)
                .last("ORDER BY FIELD(id,"+idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4.返回
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //1 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2 保存探店笔记
        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 follows = followService.query().eq("follow_user_id", user.getId()).list();
        //4 推送笔记id给所有粉丝
        for(Follow follow : follows){
            //4.1 获取粉丝id
            Long userId = follow.getUserId();
            //4.2推送
            String key = "feed:" + userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        //5 返回id
        return Result.ok(blog.getId());
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}

实战篇09

实战篇10

 thinking：JAVA中的long和int有什么区别？

 java long 区别_java中long和int的区别-CSDN博客

thinking：为什么long类型的变量需要加上L?float类型的变量要加上F？

运算符-04-05-隐式转换和强制转换_哔哩哔哩_bilibili

意思就是说：30本身是int类型，可是你现在想要它变成long类型。

而JAVA中的隐形转化，会自动将int类型转化未long类型。

因此，JAVA把你想做的事情帮你做了。因此，long num1 = 30 才可以成立

而1111111111111111111超过了int的取值范围，就已经出bug了。无法再帮你转long类型了

而double的取值范围最大，就无法自动转化了。得自己手动转化才可以。 

为什么定义long类型跟float类型的变量时要加L和F_java中long类型为什么要加l_Cristo_Li的博客-CSDN博客

【Java】double｜float 区别_java float和double-CSDN博客

 

listByIds 无法保证在数据库中按照一定的顺序进行查找，因此要用自定义sql语句才可以完成这个操作。

package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

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

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * 

 *  服务实现类
 * 
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;
    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List records = page.getRecords();
        // 查询用户
        records.forEach(blog -> {
            this.queryBlogUser(blog);
            this.isBlockLiked(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result queryBlogById(Long id) {
        //1. 查询blog
        Blog blog  =getById(id);
        if(blog == null){
            return Result.fail("笔记不存在！");
        }
        //2. 查询blog有关的用户
        queryBlogUser(blog);
        //3.查询blog是否被点赞
        isBlockLiked(blog);
        return Result.ok(blog);
    }

    private void isBlockLiked(Blog blog) {
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        if(user == null){
            //用户未登录，无需查询是否点赞
            return;
        }
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key ="blog:liked:"+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score != null);

    }

    @Override
    public Result likeBlog(Long id) {
        //1.判断当前登录用户
        Long userId = UserHolder.getUser().getId();
        //2.判断当前登录用户是否已经点赞
        String key =BLOG_LIKED_KEY+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null) {
            //3.如果未点赞，可以点赞
            //3.1数据库点赞数 +1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2保存用户到Redis的set集合
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().add(key, userId.toString(),System.currentTimeMillis());
            }
        }else {
            //4如果已点赞，取消点赞
            //4.1数据库点赞数 -1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //4.2把用户从Redis的set集合移除
            if (isSuccess) {
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key =BLOG_LIKED_KEY + id;
        //1.查询top5的点赞用户 zrange key 0 4
        Set top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5 ==null || top5.isEmpty()){
            return  Result.ok(Collections.emptyList());
        }
        //2.解析出其中的用户id
        List ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        //3.根据用户id查询用户
        List userDTOS = userService.query()
                .in("id",ids)
                .last("ORDER BY FIELD(id,"+idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        //4.返回
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //1 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2 保存探店笔记
        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 follows = followService.query().eq("follow_user_id", user.getId()).list();
        //4 推送笔记id给所有粉丝
        for(Follow follow : follows){
            //4.1 获取粉丝id
            Long userId = follow.getUserId();
            //4.2推送
            String key = "feed:" + userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        //5 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        //2.查询收件箱
        String key = FEED_KEY + userId;
        Set> typedTuples = stringRedisTemplate
                .opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        //3.非空判断
        if(typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //4.解析数据 ：blogId minTime(时间戳) offset
        List ids =new ArrayList<>(typedTuples.size());
        long minTime =0;
        int os = 1;
        for(ZSetOperations.TypedTuple tuple : typedTuples){
            //4.1 获取id
            ids.add(Long.valueOf(tuple.getValue()));
            //4.2 获取分数（时间戳）
            long time = tuple.getScore().longValue();
            if(time == minTime){
                os++;
            }else{
                minTime = time ;
                os = 1 ;
            }
        }
        //5.根据id查询blog
        String idStr = StrUtil.join(",",ids);
        List blogs = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();
        for (Blog blog : blogs) {
            //5.1 查询blog有关的用户
            queryBlogUser(blog);
            //5.2 查询blog是否被点赞
            isBlockLiked(blog);
        }

        //6 封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);

        return Result.ok(r);

    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }
}