redis——实战关注

效果： 

思路：很好想，把自己的粉丝和自己关注的人都存起来（set即可），做增删改查。

  

   

    

     

    
    

     

      package com.now.community.community.service;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import com.now.community.community.entity.User;
     
    
   

    

     

    
    

     

      import com.now.community.community.util.CommunityConstant;
     
    
   

    

     

    
    

     

      import com.now.community.community.util.RedisKeyUtil;
     
    
   

    

     

    
    

     

      import org.springframework.beans.factory.annotation.Autowired;
     
    
   

    

     

    
    

     

      import org.springframework.dao.DataAccessException;
     
    
   

    

     

    
    

     

      import org.springframework.data.redis.core.RedisOperations;
     
    
   

    

     

    
    

     

      import org.springframework.data.redis.core.RedisTemplate;
     
    
   

    

     

    
    

     

      import org.springframework.data.redis.core.SessionCallback;
     
    
   

    

     

    
    

     

      import org.springframework.stereotype.Service;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      import java.util.*;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

      @Service
     
    
   

    

     

    
    

     

      public class FollowService implements CommunityConstant {
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 @Autowired
     
    
   

    

     

    
    

     
 private RedisTemplate redisTemplate;
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 @Autowired
     
    
   

    

     

    
    

     
 private UserService userService;
     
    
   

    

     

    
    

     
 public void follow(int userId, int entityType, int entityId) {
     
    
   

    

     

    
    

     

       redisTemplate.execute(new SessionCallback() {
     
    
   

    

     

    
    

     
 @Override
     
    
   

    

     

    
    

     
 public Object execute(RedisOperations operations) throws DataAccessException {
     
    
   

    

     

    
    

     

       String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
     
    
   

    

     

    
    

     

       String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       operations.multi();
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       operations.opsForZSet().add(followeeKey, entityId, System.currentTimeMillis());
     
    
   

    

     

    
    

     

       operations.opsForZSet().add(followerKey, userId, System.currentTimeMillis());
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 return operations.exec();
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     

       });
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 public void unfollow(int userId, int entityType, int entityId) {
     
    
   

    

     

    
    

     

       redisTemplate.execute(new SessionCallback() {
     
    
   

    

     

    
    

     
 @Override
     
    
   

    

     

    
    

     
 public Object execute(RedisOperations operations) throws DataAccessException {
     
    
   

    

     

    
    

     

       String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
     
    
   

    

     

    
    

     

       String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       operations.multi();
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       operations.opsForZSet().remove(followeeKey, entityId);
     
    
   

    

     

    
    

     

       operations.opsForZSet().remove(followerKey, userId);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 return operations.exec();
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     

       });
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 // 查询关注的实体的数量
     
    
   

    

     

    
    

     
 public long findFolloweeCount(int userId, int entityType) {
     
    
   

    

     

    
    

     

       String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
     
    
   

    

     

    
    

     
 return redisTemplate.opsForZSet().zCard(followeeKey);
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 // 查询实体的粉丝的数量
     
    
   

    

     

    
    

     
 public long findFollowerCount(int entityType, int entityId) {
     
    
   

    

     

    
    

     

       String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
     
    
   

    

     

    
    

     
 return redisTemplate.opsForZSet().zCard(followerKey);
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 // 查询当前用户是否已关注该实体
     
    
   

    

     

    
    

     
 public boolean hasFollowed(int userId, int entityType, int entityId) {
     
    
   

    

     

    
    

     

       String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
     
    
   

    

     

    
    

     
 return redisTemplate.opsForZSet().score(followeeKey, entityId) != null;
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 // 查询某用户关注的人
     
    
   

    

     

    
    

     
 public List<Map<String, Object>> findFollowees(int userId, int offset, int limit) {
     
    
   

    

     

    
    

     

       String followeeKey = RedisKeyUtil.getFolloweeKey(userId, ENTITY_TYPE_USER);
     
    
   

    

     

    
    

     

       Set<Integer> targetIds = redisTemplate.opsForZSet().reverseRange(followeeKey, offset, offset + limit - 1);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 if (targetIds == null) {
     
    
   

    

     

    
    

     
 return null;
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       List<Map<String, Object>> list = new ArrayList<>();
     
    
   

    

     

    
    

     
 for (Integer targetId : targetIds) {
     
    
   

    

     

    
    

     

       Map<String, Object> map = new HashMap<>();
     
    
   

    

     

    
    

     

       User user = userService.findUserById(targetId);
     
    
   

    

     

    
    

     

       map.put("user", user);
     
    
   

    

     

    
    

     

       Double score = redisTemplate.opsForZSet().score(followeeKey, targetId);
     
    
   

    

     

    
    

     

       map.put("followTime", new Date(score.longValue()));
     
    
   

    

     

    
    

     

       list.add(map);
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 return list;
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 // 查询某用户的粉丝
     
    
   

    

     

    
    

     
 public List<Map<String, Object>> findFollowers(int userId, int offset, int limit) {
     
    
   

    

     

    
    

     

       String followerKey = RedisKeyUtil.getFollowerKey(ENTITY_TYPE_USER, userId);
     
    
   

    

     

    
    

     

       Set<Integer> targetIds = redisTemplate.opsForZSet().reverseRange(followerKey, offset, offset + limit - 1);
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 if (targetIds == null) {
     
    
   

    

     

    
    

     
 return null;
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     

       List<Map<String, Object>> list = new ArrayList<>();
     
    
   

    

     

    
    

     
 for (Integer targetId : targetIds) {
     
    
   

    

     

    
    

     

       Map<String, Object> map = new HashMap<>();
     
    
   

    

     

    
    

     

       User user = userService.findUserById(targetId);
     
    
   

    

     

    
    

     

       map.put("user", user);
     
    
   

    

     

    
    

     

       Double score = redisTemplate.opsForZSet().score(followerKey, targetId);
     
    
   

    

     

    
    

     

       map.put("followTime", new Date(score.longValue()));
     
    
   

    

     

    
    

     

       list.add(map);
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     
 
     
    
   

    

     

    
    

     
 return list;
     
    
   

    

     

    
    

     

       }
     
    
   

    

     

    
    

     

      }
     
    
  
 

文章来源: fantianzuo.blog.csdn.net，作者：兔老大RabbitMQ，版权归原作者所有，如需转载，请联系作者。

原文链接：fantianzuo.blog.csdn.net/article/details/102798814