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redis分布式秒杀锁

news 2025/6/22 12:48:22

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-- 获取锁标识，是否与当前线程一致？
if(redis.call('get', KEYS[1]) == ARGV[1]) then-- 一致，删除return redis.call('del', KEYS[1])
end
-- 不一致，直接返回
return 0

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package com.platform.lock;public interface ILock {/*** 获取锁* @param timeoutSec* @return*/public boolean tryLock(long timeoutSec);/*** 锁标识、释放锁*/public void unlock();
}

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package com.platform.lock;import cn.hutool.core.lang.UUID;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;import java.util.Collections;
import java.util.concurrent.TimeUnit;/*** redis的分布式锁* 实现ILock接口*/
public class SimpleRedisLock implements ILock {// 不同的业务有不同的锁名称private String name;private StringRedisTemplate stringRedisTemplate;private static final String KEY_PREFIX = "tryLock:";private static final String ID_PREFIX = UUID.randomUUID().toString(true) + "-";// DefaultRedisScript，private static final DefaultRedisScript<Long> UNLOCK_SCRIPT;public SimpleRedisLock(String name, StringRedisTemplate stringRedisTemplate) {this.name = name;this.stringRedisTemplate = stringRedisTemplate;}// 初始化 UNLOCK_SCRIPT，用静态代码块的方式，一加载SimpleRedisLock有会加载unlock.lua// 避免每次调unLock() 才去加载，提升性能！！！static {UNLOCK_SCRIPT = new DefaultRedisScript<>();// setLocation() 设置脚本位置UNLOCK_SCRIPT.setLocation(new ClassPathResource("unlock.lua"));// 返回值类型UNLOCK_SCRIPT.setResultType(Long.class);}/*** 获取锁*/@Overridepublic boolean tryLock(long timeoutSec) {// 获取线程标示String threadId = ID_PREFIX + Thread.currentThread().getId();// 获取锁// set lock thread1 nx ex 10// nx : setIfAbsent(如果不存在) , ex : timeoutSec(秒)Boolean success = stringRedisTemplate.opsForValue().setIfAbsent(KEY_PREFIX + name, threadId, timeoutSec, TimeUnit.SECONDS);// 自动拆箱（Boolean -> boolean）！！！可能有风险return Boolean.TRUE.equals(success);}/*** 解决判断（锁标识、释放锁）这两个动作，之间产生阻塞！！！* JVM的 FULL GC* 要让这两个动作具有原子性*/@Overridepublic void unlock() {// 调用lua脚本stringRedisTemplate.execute(UNLOCK_SCRIPT,Collections.singletonList(KEY_PREFIX + name),ID_PREFIX + Thread.currentThread().getId());}
}

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    @PostMapping("/cancelPublicBenefit")@CheckRepeatCommitpublic RestResponse cancelPublicBenefit(@LoginUser MallUserEntity loginUser, @RequestBody MallPublicBenefitEntity publicBenefitEntity) {String key = PUBLIC_BENEFIT_TEAM_LOCK_FLAG + publicBenefitEntity.getId();RestResponse restResponse = null;SimpleRedisLock simpleRedisLock = new SimpleRedisLock(key,stringRedisTemplate);try {if (simpleRedisLock.tryLock(15)) {// 成功获取锁，执行业务逻辑restResponse = mallPublicBenefitService.cancelPublicBenefit(loginUser, publicBenefitEntity);} else {// 获取锁失败，处理失败逻辑throw new BusinessException("服务器繁忙！");}} finally {simpleRedisLock.unlock();}return restResponse;}

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