如何使用Redis实现点赞取消点赞

代码实现:

/**
     *
     * @param userId 点赞的人
     * @param type 点赞与取消点赞的表示
     * @param textId   文章ID
     * @param entityUserId -- 被点赞的人，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);
                //多个更新操作，需要事务
                operations.multi();
                if (isMember) {
                    //取消赞
                    redisTemplate.opsForSet().remove(entityLikeKey, userId);
                    redisTemplate.opsForValue().decrement(userLikeKey);
                } else {
                    //点赞
                    redisTemplate.opsForSet().add(entityLikeKey, userId);
                    redisTemplate.opsForValue().increment(userLikeKey);
                }
                return operations.exec();
            }
        });

    }

    /**
     *查询某实体（帖子，评论等）点赞数量
     * @param type 1点赞，2评论。0表示取消点赞
     * @param textId
     * @return
     */
    private long findEntityLikeCount(int type, int textId){
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(type, textId);
        return redisTemplate.opsForSet().size(entityLikeKey);
    }

    /**
     * 查询某人对某文章的点赞状态
     * @param textId 帖子ID
     * @param userId
     * @return
     */
    private int findEntityLikeStatus(int textId,long userId){
        String entityLikeKey = RedisKeyUtil.getEntityLikeKey(1, textId);
        //此处返回int，是为了进行扩展。比如扩展踩，为止2.等等情况
        return redisTemplate.opsForSet().isMember(entityLikeKey,userId)?1:0;
    }

    /**
     * 查询某个用户获得赞，用于在个人主页查看收获了多少赞
     * @param userId
     * @return
     */
    private int findUserLikeCount(long userId){
        String userLikeKey = RedisKeyUtil.getUserLikeKey(userId);
        Integer count = (Integer) redisTemplate.opsForValue().get(userLikeKey);
        // count.intValue()数据的整数形式;
        return count==null?0:count.intValue();
    }

redis–key设置

Remover

几秒钟去除图中不需要的元素

下载

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";
    /**
     *某个实体收到的赞，如帖子，
     * like:entity:entityType:entityId -> set(userId) 对应set，存入userId
     * @param entityType
     * @param entityId
     * @return
     */
    public static String getEntityLikeKey(int entityType, int entityId) {
        return PREFIX_ENTITY_LIKE + entityType + SPLIT + entityId;
    }
     *某个用户收到的总赞数
     * like:user:userId ->long
     * @param userId
    public static String getUserLikeKey(long userId) {
        return PREFIX_USER_LIKE + SPLIT + userId;
     * 汇总某个帖子的评论数量
    public static String getUserCommentsKey(int articleId) {
        return PREFIX_USER_COMMENTS + SPLIT + articleId;