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Redis保证事务一致性，以及常用的数据结构

news 来源：原创 2024/5/21 10:34:20

reids命令可以参考中文官网：http://redis.cn/commands.html

关于reids的使用，可以封装到工具类进行调用：

Redis的工具类：JedisAdapter

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除了数据结构：reids还可以用来保持事务的一致性；例如：

1：关于Redis的事务：利用reids的exec命令保证执行，不然就discard回滚

例如声明两个方法：

Transaction multi(Jedis jedis)

List<Object> exec(Transaction tx, Jedis jedis)

    public Transaction multi(Jedis jedis) {
                try {
                    return jedis.multi();
                } catch (Exception e) {
                    logger.error("发生异常" + e.getMessage());
                } finally {
                }
                return null;
            }
        
            public List<Object> exec(Transaction tx, Jedis jedis) {
                try {
                    return tx.exec(); //保证事务执行
                } catch (Exception e) {
                    logger.error("发生异常" + e.getMessage());
                    tx.discard();   //回滚
                } finally {
                    if (tx != null) {
                        try {
                            tx.close();
                        } catch (IOException ioe) {
                            // ..
                        }
                    }
                    if (jedis != null) {
                        jedis.close();
                    }
                }
                return null;
            }

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2：对于两个方法的使用：

 public boolean follow(int userId, int entityType, int entityId) {
        String followerKey = RedisKeyUtil.getFollowerKey(entityType, entityId);
        String followeeKey = RedisKeyUtil.getFolloweeKey(userId, entityType);
        Date date = new Date();
        // 实体的粉丝增加当前用户
        Jedis jedis = jedisAdapter.getJedis();
        Transaction tx = jedisAdapter.multi(jedis);
        tx.zadd(followerKey, date.getTime(), String.valueOf(userId));
        // 当前用户对这类实体关注+1
        tx.zadd(followeeKey, date.getTime(), String.valueOf(entityId));
        List<Object> ret = jedisAdapter.exec(tx, jedis);
        return ret.size() == 2 && (Long) ret.get(0) > 0 && (Long) ret.get(1) > 0;
    }

followee/follower两个队列

3：常见的redis数据结构和使用：

   List：双向列表，适用于最新列表，关注列表
   lpush
   lpop
   blpop
   lindex
   lrange
   lrem
   linsert
   lset
   rpush
Set：适用于无顺序的集合，点赞点踩，抽奖，已读，共同好友

   sdiff
   smembers
   sinter
   scard
 SortedSet：排行榜，优先队列

   zadd
   zscore
   zrange
   zcount
   zrank
   zrevrank
 Hash：对象属性，不定长属性数

   hset
   hget
   hgetAll
   hexists
   hkeys
   hvals
 KV：单一数值，验证码，PV，缓存
   set
   setex
   incr

Jedis jedis = new Jedis("redis://localhost:6379/9");
jedis.flushDB();

// get set
jedis.set("hello", "world");
print(1, jedis.get("hello"));
jedis.rename("hello", "newhello");
print(1, jedis.get("newhello"));
jedis.setex("hello2", 1800, "world");

//
jedis.set("pv", "100");
jedis.incr("pv");
jedis.incrBy("pv", 5);//一次加五
print(2, jedis.get("pv"));
jedis.decrBy("pv", 2);
print(2, jedis.get("pv"));

print(3, jedis.keys("*"));//打印出来所有的key


//
String listName = "list";
jedis.del(listName);
for (int i = 0; i < 10; ++i) {
    jedis.lpush(listName, "a" + String.valueOf(i));
}
print(4, jedis.lrange(listName, 0, 12));
print(4, jedis.lrange(listName, 0, 3));
print(5, jedis.llen(listName));//长度
print(6, jedis.lpop(listName));//先进后出，pop
print(7, jedis.llen(listName));//长度
print(8, jedis.lrange(listName, 2, 6));
print(9, jedis.lindex(listName, 3));
print(10, jedis.linsert(listName, BinaryClient.LIST_POSITION.AFTER, "a4", "xx"));//插入
print(10, jedis.linsert(listName, BinaryClient.LIST_POSITION.BEFORE, "a4", "bb"));//删除
print(11, jedis.lrange(listName, 0 ,12)) ;

// hash
String userKey = "userxx";
jedis.hset(userKey, "name", "jim");
jedis.hset(userKey, "age", "12");
jedis.hset(userKey, "phone", "18618181818");
print(12, jedis.hget(userKey, "name"));
print(13, jedis.hgetAll(userKey));
jedis.hdel(userKey, "phone");
print(14, jedis.hgetAll(userKey));
print(15, jedis.hexists(userKey, "email"));
print(16, jedis.hexists(userKey, "age"));
print(17, jedis.hkeys(userKey));
print(18, jedis.hvals(userKey));
jedis.hsetnx(userKey, "school", "zju");
jedis.hsetnx(userKey, "name", "yxy");
print(19, jedis.hgetAll(userKey));

// set集和
String likeKey1 = "commentLike1";
String likeKey2 = "commentLike2";
for (int i = 0; i < 10; ++i) {
    jedis.sadd(likeKey1, String.valueOf(i));
    jedis.sadd(likeKey2, String.valueOf(i*i));
}
print(20, jedis.smembers(likeKey1)); //smembers（key）取值
print(21, jedis.smembers(likeKey2));
print(22, jedis.sunion(likeKey1, likeKey2));//求并集
print(23, jedis.sdiff(likeKey1, likeKey2)); //补集
print(24, jedis.sinter(likeKey1, likeKey2));//交集
print(25, jedis.sismember(likeKey1, "12"));//判断是否存在
print(26, jedis.sismember(likeKey2, "16"));//判断
jedis.srem(likeKey1, "5");
print(27, jedis.smembers(likeKey1));
jedis.smove(likeKey2, likeKey1, "25"); //从一移进2一个25
print(28, jedis.smembers(likeKey1));
print(29, jedis.scard(likeKey1)); //求总和

String rankKey = "rankKey";//优先队列zset（）
jedis.zadd(rankKey, 15, "jim");
jedis.zadd(rankKey, 60, "Ben");
jedis.zadd(rankKey, 90, "Lee");
jedis.zadd(rankKey, 75, "Lucy");
jedis.zadd(rankKey, 80, "Mei");
print(30, jedis.zcard(rankKey));// zcard（）输出
print(31, jedis.zcount(rankKey, 61, 100));
print(32, jedis.zscore(rankKey, "Lucy"));
jedis.zincrby(rankKey, 2, "Lucy");
print(33, jedis.zscore(rankKey, "Lucy"));
jedis.zincrby(rankKey, 2, "Luc");
print(34, jedis.zscore(rankKey, "Luc"));
print(35, jedis.zrange(rankKey, 0, 100));
print(36, jedis.zrange(rankKey, 0, 10));//范围输出
print(36, jedis.zrange(rankKey, 1, 3));
print(36, jedis.zrevrange(rankKey, 1, 3));//从低到高排列
for (Tuple tuple : jedis.zrangeByScoreWithScores(rankKey, "60", "100")) {
    print(37, tuple.getElement() + ":" + String.valueOf(tuple.getScore()));
}

print(38, jedis.zrank(rankKey, "Ben"));
print(39, jedis.zrevrank(rankKey, "Ben"));

String setKey = "zset";
jedis.zadd(setKey, 1, "a");
jedis.zadd(setKey, 1, "b");
jedis.zadd(setKey, 1, "c");
jedis.zadd(setKey, 1, "d");
jedis.zadd(setKey, 1, "e");

print(40, jedis.zlexcount(setKey, "-", "+"));
print(41, jedis.zlexcount(setKey, "(b", "[d"));//不包含
print(42, jedis.zlexcount(setKey, "[b", "[d"));//包含，b到d
jedis.zrem(setKey, "b");
print(43, jedis.zrange(setKey, 0, 10));
jedis.zremrangeByLex(setKey, "(c", "+");
print(44, jedis.zrange(setKey, 0 ,2));

/*连接池
JedisPool pool = new JedisPool();
for (int i = 0; i < 100; ++i) {
    Jedis j = pool.getResource();
    print(45, j.get("pv"));
    j.close();
}*/

User user = new User();
user.setName("xx");
user.setPassword("ppp");
user.setHeadUrl("a.png");
user.setSalt("salt");
user.setId(1);
print(46, JSONObject.toJSONString(user));//序列化user
jedis.set("user1", JSONObject.toJSONString(user));

String value = jedis.get("user1");
User user2 = JSON.parseObject(value, User.class);//反序列化，转化为user对象；
print(47, user2);
int k = 2;