• Daily Archives: 2022年8月9日

java使用jedis执行lua脚本

1、引入依赖

		<!-- Jedis -->
		<dependency>
			<groupId>redis.clients</groupId>
			<artifactId>jedis</artifactId>
		</dependency>

2、编写配置文件

#Redis
spring.redis.host=127.0.0.1
spring.redis.port=6379
spring.redis.database=3

spring.redis.password=
spring.redis.timeout=2000

#Jedis
#最大空闲数
spring.redis.jedis.pool.max-idle=6
#最大连接数
spring.redis.jedis.pool.max-active=10
#最小空闲数
spring.redis.jedis.pool.min-idle=2
#连接超时
spring.redis.jedis.pool.timeout=2000

3、编写配置类

package com.zero4j.config;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPoolConfig;

@Configuration
public class JedisConfig {

    private Logger logger = LoggerFactory.getLogger(JedisConfig.class);

    @Value("${spring.redis.host}")
    private String host;

    @Value("${spring.redis.port}")
    private int port;

    @Value("${spring.redis.password}")
    private String password;
    @Value("${spring.redis.timeout}")
    private int timeout;

    @Value("${spring.redis.jedis.pool.max-active}")
    private int maxActive;

    @Value("${spring.redis.jedis.pool.max-idle}")
    private int maxIdle;

    @Value("${spring.redis.jedis.pool.min-idle}")
    private int minIdle;

    @Bean
    public JedisPool jedisPool(){

        JedisPoolConfig jedisPoolConfig=new JedisPoolConfig();
        jedisPoolConfig.setMaxIdle(maxIdle);
        jedisPoolConfig.setMinIdle(minIdle);
        jedisPoolConfig.setMaxTotal(maxActive);

        JedisPool jedisPool = new JedisPool(jedisPoolConfig,host,port,timeout,password);

        logger.info("JedisPool连接成功:"+host+"\t"+port);

        return jedisPool;
    }

}

4、实现业务逻辑

	@Autowired
	private JedisPool jedisPool;

 

		Jedis jedis = null;

		try {
			jedis = jedisPool.getResource();
			String poolId = "pool1";
			String poolLuaRedisKey = "cardLottery." + poolId + "-lua-shaKey";
			String poolLuaRedisValue = jedis.get(poolLuaRedisKey);
			byte[] shaKey = null;
			if(poolLuaRedisValue!=null){
				shaKey = poolLuaRedisValue.getBytes();
			}
			if (shaKey == null) {
				ClassPathResource cps = new ClassPathResource("lua/test.lua");
				InputStream in = cps.getInputStream();
				byte[] data = new byte[in.available()];
				in.read(data);
				shaKey = jedis.scriptLoad(data);
				jedis.set("cardLottery." + poolId + "-lua-shaKey", new String(shaKey));
			}

			System.out.println("本次执行的lua脚本的sha为：" + new String(shaKey));

			List<String> keys = new ArrayList<>();
			keys.add(poolId);
			keys.add("100");
			keys.add("0.5");
			List<String> vals = new ArrayList<>();
			for (int i = 0; i < 10; i++) {
				Date _startTime = new Date();
				Object result = jedis.evalsha(new String(shaKey), keys, vals);
				Date _endTime = new Date();
				long _timeCross = _endTime.getTime() - _startTime.getTime();
				System.out.println("lua的第" + (i + 1) + "次执行花了" + _timeCross + "毫秒，执行结果：" + result);
			}
		}catch(Exception e){
			e.printStackTrace();
		}finally {
			if(jedis!=null){
				jedis.close();
			}
		}

5、Lua脚本

local key = 'cardPool.'..KEYS[1]..'-bucket' -- redis中令牌桶对象的key
local initTokens = tonumber(KEYS[2]) -- {初始化时的令牌数}
local probability = tonumber(KEYS[3]) -- {中奖概率：小于0的数字（百分比概念）}

print(probability)

local bucket = redis.call('hgetall', key) -- 当前 key 的令牌桶对象
local currentTokens -- 当前token数量
local runCount -- 累计执行次数统计

-- 若当前桶未初始化,先初始化令牌桶
if table.maxn(bucket) == 0 then
    -- 初始桶内令牌
    currentTokens = initTokens
    runCount = 0
    redis.call('hset', key, 'stock', currentTokens)
    redis.call('hset', key, 'probability', probability)
    redis.call('hset', key, 'runCount', 0)
elseif table.maxn(bucket) == 6 then
    currentTokens = tonumber(bucket[2])
    probability = tonumber(bucket[4])
    runCount = tonumber(bucket[6])
end

-- 如果当前桶内令牌小于 0,抛出异常
assert(currentTokens >= 0)

redis.call('hset', key, 'runCount', runCount + 1)

if currentTokens == 0 then  -- 如果当前令牌 == 0, 返回false
    return -1
else    -- 如果当前令牌 大于 0, 则执行抽奖逻辑
    if probability<> nil or probability >= 1 or math.random() <= probability then -- 如果中奖概率大于或等于1，生成随机的小数如果在probability内，则中奖
        -- 更新当前桶内的令牌 -1, 返回true
        redis.call('hset', key, 'stock', currentTokens - 1)
        return 1
    else
        return 0
    end
end

注意：如果Lua脚本返回是true和false的类型，则jedis实际获得的值为1和null。

 

close