RedisTemplate zSet的使用, 根据点赞排序,和创建时间排序2种方式

使用Redis 对问题下的回答按点赞数排序的思路;

1根据问题id查出所有的回答列表;

2吧回答的ids添加到zset1中; key为id,value为赞的数量;(用于点赞排行);

//批量添加 Long add(K var1, Set<ZSetOperations.TypedTuple<V>>var2);

2-2吧回答的ids添加到zset2中;key为id,value为createTime.getLong();(用于创建时间排行);

3对回答进行点赞(取消)的时候

更改zset1中的指定key的value加减1;

4-1发表回答的时候zset1,zset2中增加元素,

 //redisTemplate.opsForZSet().add(key,4565L,13);

4-2删除的时候移除元素;

//redisTemplate.opsForZSet().remove(key,4565L)

5获取排序后的分页数据;结果为回答的ids;

6迭代ids 去每个回答的id对应素材的缓存中取出对象;

    @Test   public void test2(){      String key = "mls_AnswerIdsByQuersionId:"+123;      redisTemplate.opsForZSet().add(key,234L,5); //添加单条      redisTemplate.opsForZSet().add(key,4565L,13);      redisTemplate.opsForZSet().add(key,2345L,15);      Set<ZSetOperations.TypedTuple<Long>> var2 = new HashSet<>();      ZSetOperations.TypedTuple<Long> answerVoInZset1 = new AnswerVoInZset(2345L, 12);      ZSetOperations.TypedTuple<Long> answerVoInZset2 = new AnswerVoInZset(5675L, 16);      ZSetOperations.TypedTuple<Long> answerVoInZset4 = new AnswerVoInZset(4565L, 11);      var2.add(answerVoInZset1);      var2.add(answerVoInZset2);      var2.add(answerVoInZset4);      redisTempalte.opsForZSet().add(key, var2);//批量添加      redisTemplate.opsForZSet().remove(key,4565L); //移除单个元素      Set<Long> longs = redisTempalte.opsForZSet().reverseRange(key, 0, 3);   }//用于批量添加的对象;   class AnswerVoInZset implements ZSetOperations.TypedTuple<Long>{      Long id;      double score;      public AnswerVoInZset(Long id, double score) {         this.id = id;         this.score = score;      }      @Override      public Long getValue() {         return id;      }      @Override      public Double getScore() {         return score;      }      @Override      public int compareTo(ZSetOperations.TypedTuple<Long> o) {         AnswerVoInZset o1 = (AnswerVoInZset) o;         return new Double(this.score).compareTo(o1.getScore());      }   }   //时间排序;(参考别人的)   @Resource(name = "redisTemplate")   private RedisTemplate<String, Long> redisTempalte;   public void addRecentBrowsingPosition(long userId, long positionId) {      String key = "mls_AnswerIdsByQuersionId:" + 123;      // 获取已缓存的最近浏览的职位      ZSetOperations<String, Long> zSetOperations = redisTempalte.opsForZSet();      // zset内部是按分数来排序的，这里用当前时间做分数      zSetOperations.add(key, positionId, System.currentTimeMillis());      // 环形结构--4,-3,-2,-1,0,1,2,3,4      zSetOperations.removeRange(key, 0, -6);   }   public List<Long> getRecentBrowsingPositionIds(long userId) {      if (userId <= 0) {         return Collections.emptyList();      }      // 获取用户最近浏览的职位id      String key = "mls_AnswerIdsByQuersionId:" + 123;      Set<Long> positionIds = redisTempalte.opsForZSet().reverseRange(key, 0, 4);      return new ArrayList<>(positionIds);   }