# 獲取商品庫(kù)存數(shù)量
def get_stock(product_id):
    redis_conn = Redis()
    stock = redis_conn.get(f'stock:{product_id}')
    return int(stock) if stock else 0

# 更新商品庫(kù)存數(shù)量
def update_stock(product_id, quantity):
    redis_conn = Redis()
    redis_conn.incrby(f'stock:{product_id}', quantity)

# 判斷商品庫(kù)存是否充足
def check_stock(product_id, quantity):
    stock = get_stock(product_id)
    return stock >= quantity

# 避免超賣問(wèn)題
def avoid_over_sell(product_id, quantity):
    redis_conn = Redis()
    with redis_conn.pipeline() as pipe:
        while True:
            try:
                pipe.watch(f'stock:{product_id}')
                stock = pipe.get(f'stock:{product_id}')
                stock = int(stock) if stock else 0
                if stock < quantity:
                    pipe.unwatch()
                    raise Exception('庫(kù)存不足')
                pipe.multi()
                pipe.decrby(f'stock:{product_id}', quantity)
                pipe.execute()
                break
            except WatchError:
                continue

		// 庫(kù)存存在則加一
        if(redisService.get(prefix, key, Integer.class) != null){
            redisService.incr(prefix, key);
        }

        // 首先獲取當(dāng)前訪問(wèn)頻次
		Integer count = redisService.get(prefix, key, Integer.class);
        // 如果頻次為空，則設(shè)置訪問(wèn)次數(shù)為1
		if (count == null) {
            redisService.set(prefix, key, 1);
        } else if (count < checkFrequencyCount) {
            // 如果頻次小于限制，則設(shè)置訪問(wèn)次數(shù)加1
            redisService.incr(prefix, key);
        } else {
			// 如果頻次超過(guò)限制，則限流
            throw new AppException("訪問(wèn)頻次過(guò)高，請(qǐng)稍候再試");
        }

		long count = redisService.incr(prefix, key);
		// 判斷必須放在后面，否則key沒(méi)有過(guò)期時(shí)間永遠(yuǎn)無(wú)法清除
        long expire = redisService.ttl(prefix, key);
        if (expire == -1) {
            redisService.setExpire(prefix, key, accessExpireSecond);
        }
        if (count > checkFrequencyCount) {
            throw new AppException("訪問(wèn)頻次過(guò)高，請(qǐng)稍候再試");
        }

--- 獲取key
local key = KEYS[1]
--- 獲取參數(shù):incr、decr
local action = ARGV[1]
--- 如果key存在，再執(zhí)行增加或減少的操作
if redis.call('exists', key) == 1 
then redis.call(action, key)
    return true
end 
return false

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.scripting.support.ResourceScriptSource;

@Configuration
public class LuaConfiguration {
    @Bean(name = "update")
    public DefaultRedisScript<Boolean> redisScript() {
        DefaultRedisScript<Boolean> redisScript = new DefaultRedisScript<>();
        redisScript.setScriptSource(new ResourceScriptSource(new ClassPathResource("luascript/updateStore.lua")));
        redisScript.setResultType(Boolean.class);
        return redisScript;
    }
}

    @Resource(name = "update")
    private DefaultRedisScript<Boolean> redisScript;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
	// 執(zhí)行腳本并傳參
	Boolean result = stringRedisTemplate.execute(redisScript, Arrays.asList(stockPrefix.getPrefix() + key), "incr");