# 如果key不存，set key=value，
# 失效時(shí)間是 expiration毫秒
SET key value NX PX expiration

import org.redisson.Redisson;
import org.redisson.api.RedissonClient;
import org.redisson.config.Config;

public class RedissonExample {
    public static void main(String[] args) {
        Config config = new Config();
        config.useSingleServer().setAddress("redis://127.0.0.1:6379");
        RedissonClient redisson = Redisson.create(config);

        // 使用分布式鎖
        String lockKey = "lockKey";
        boolean isLocked = redisson.getLock(lockKey).tryLock();
        if (isLocked) {
            // 獲得鎖，執(zhí)行相關(guān)操作
            System.out.println("Lock acquired successfully");
            redisson.getLock(lockKey).unlock(); // 釋放鎖
        } else {
            System.out.println("Failed to acquire lock");
        }
        redisson.shutdown(); // 關(guān)閉連接
    }
}

import redis.clients.jedis.Jedis;
import redis.clients.jedis.Response;
import redis.clients.jedis.Transaction;

public class RateLimiter {
    private final Jedis jedis;
    private final String key;
    private final int capacity;
    private final int tokensPerSecond;

    public RateLimiter(Jedis jedis, String key, int capacity, int tokensPerSecond) {
        this.jedis = jedis;
        this.key = key;
        this.capacity = capacity;
        this.tokensPerSecond = tokensPerSecond;
    }
   
    /**
    * 用于檢查是否允許請求，根據(jù)當(dāng)前令牌數(shù)量和容量進(jìn)行判斷
    */ 
    public boolean allowRequest() {
        long now = System.currentTimeMillis();
        Transaction transaction = jedis.multi();
        // Add current time with score
        transaction.zadd(key, now, String.valueOf(now)); 
        // Remove tokens that are older than 1 second
        transaction.zremrangeByScore(key, 0, now - 1000); 
        // Get current number of tokens
        Response<Long> sizeResponse = transaction.zcard(key); 

        transaction.exec();

        long size = sizeResponse.get();
        // Check if number of tokens is within capacity
        return size <= capacity; 
    }

    public static void main(String[] args) {
        Jedis jedis = new Jedis("localhost"); // Connect to Redis
        // Create rate limiter
        RateLimiter rateLimiter = new RateLimiter(jedis, "RateLimiterKey", 10, 5); 

        for (int i = 0; i < 15; i++) {
            boolean allowed = rateLimiter.allowRequest();
            if (allowed) {
                System.out.println("Request allowed");
            } else {
                System.out.println("Request denied");
            }
        }

        // Close Redis connection
        jedis.close(); 
    }
}

#將用戶的登錄信息存儲(chǔ)在 Redis中，key：userId， value：user登錄信息
SET user:userId {"username": "xxx", "password": "xxx",...}

#訂閱頻道
SUBSCRIBE channel_xxx
# 向頻道中發(fā)送消息
PUBLISH channel_xxx "Message content"

# 添加文章的點(diǎn)擊量
#將 Article1 的值增加1。如果Article1 不存在于有序集合中，
# 該命令會(huì)將 Article1 添加到集合，并設(shè)置值為1
ZINCRBY leaderboard 1 "Article1"
ZINCRBY leaderboard 1 "Article2"
ZINCRBY leaderboard 1 "Article3"

# 獲取 Article2的排名（從高到低排名）
ZREVRANK leaderboard "Article2" 

# 獲點(diǎn)擊量 Top10 的文章和點(diǎn)擊量
ZREVRANGE leaderboard 0 9 WITHSCORES

# 對 key進(jìn)行 +1 操作
INCR key
# 對key 進(jìn)行 -1 操作
DECR key

# 對 key進(jìn)行 +n 操作
INCRBY key n
# 對 key進(jìn)行 -n 操作
DECRBY key n

# 查找經(jīng)度12.087269，緯度39.412669 附近5 km的距離范圍
GEORADIUS locations 12.087269 39.412669 5 km

# 添加經(jīng)緯度信息，經(jīng)緯度是編造的，不一定真實(shí)
GEOADD locations 12.322389 39.125356 "Driver"
GEOADD locations 12.087269 39.412669 "Passenger"
# 計(jì)算司機(jī)和乘客兩地點(diǎn)間的距離
GEODIST locations Driver Passenger