/**
     *
     * @param userId 點贊的人
     * @param type 點贊與取消點贊的表示
     * @param textId   文章ID
     * @param entityUserId -- 被點贊的人，文章作者
     */
    private void like(long userId,int type,int textId,long entityUserId){
        redisTemplate.execute(new SessionCallback() {
            @Override
            public Object execute(RedisOperations operations) throws DataAccessException {
                String entityLikeKey = RedisKeyUtil.getEntityLikeKey(type, textId);
                String userLikeKey = RedisKeyUtil.getUserLikeKey(entityUserId);
                boolean isMember = redisTemplate.opsForSet().isMember(entityLikeKey, userId);
                //多個更新操作，需要事務
                operations.multi();
                if (isMember) {
                    //取消贊
                    redisTemplate.opsForSet().remove(entityLikeKey, userId);
                    redisTemplate.opsForValue().decrement(userLikeKey);
                } else {
                    //點贊
                    redisTemplate.opsForSet().add(entityLikeKey, userId);
                    redisTemplate.opsForValue().increment(userLikeKey);
                }
                return operations.exec();
            }
        });

    }

    /**
     *查詢某實體（帖子，評論等）點贊數量
     * @param type 1點贊，2評論。0表示取消點贊
     * @param textId
     * @return
     */
    private long findEntityLikeCount(int type, int textId){
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(type, textId);
        return redisTemplate.opsForSet().size(entityLikeKey);
    }

    /**
     * 查詢某人對某文章的點贊狀態
     * @param textId 帖子ID
     * @param userId
     * @return
     */
    private int findEntityLikeStatus(int textId,long userId){
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(1, textId);
        //此處返回int，是為了進行擴展。比如擴展踩，為止2.等等情況
        return redisTemplate.opsForSet().isMember(entityLikeKey,userId)?1:0;
    }

    /**
     * 查詢某個用戶獲得贊，用于在個人主頁查看收獲了多少贊
     * @param userId
     * @return
     */
    private int findUserLikeCount(long userId){
        String userLikeKey = RedisKeyUtil.getUserLikeKey(userId);
        Integer count = (Integer) redisTemplate.opsForValue().get(userLikeKey);
        // count.intValue()數據的整數形式;
        return count==null?0:count.intValue();
    }

public class RedisKeyUtil {
    private static final String SPLIT = ":";
    private static final String PREFIX_ENTITY_LIKE = "like:entity";
    private static final String PREFIX_USER_LIKE = "like:user";
    private static final String PREFIX_USER_COMMENTS="comments:user";
    /**
     *某個實體收到的贊，如帖子，
     * like:entity:entityType:entityId -> set(userId) 對應set，存入userId
     * @param entityType
     * @param entityId
     * @return
     */
    public static String getEntityLikeKey(int entityType, int entityId) {
        return PREFIX_ENTITY_LIKE + entityType + SPLIT + entityId;
    }
     *某個用戶收到的總贊數
     * like:user:userId ->long
     * @param userId
    public static String getUserLikeKey(long userId) {
        return PREFIX_USER_LIKE + SPLIT + userId;
     * 匯總某個帖子的評論數量
    public static String getUserCommentsKey(int articleId) {
        return PREFIX_USER_COMMENTS + SPLIT + articleId;