Redis分布式锁解决超卖问题的使用示例

SETNX lock thread1

DEL lock

EXPIRE lock 10  

set lock thread1 EX 10 NX

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

Spring:
	redis:
	    port: 6379
	    host: localhost

public interface ILock {
    /**
     * 尝试获取锁
     * @param timeoutSec 锁持有的超时时间，过期后自动释放
     * @return true代表获取锁成功; false代表获取锁失败
     */
    boolean tryLock(long timeoutSec);
    /**
     * 释放锁
     */
    void unlock();
}

public class SimpleRedisLock implements ILock  {
    private StringRedisTemplate stringRedisTemplate;
    public SimpleRedisLock(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }
    @Override
    public boolean tryLock(long timeoutSec) {
        Boolean secuss = stringRedisTemplate.opsForValue()
                .setIfAbsent("lock", "thread", timeoutSec, TimeUnit.SECONDS);
        return secuss;
    }
    @Override
    public void unlock() {
        stringRedisTemplate.delete("lock");
    }
}

@PostMapping("/kill")
    public String executeSeckillProduct(int productId,int seckillCount){
        //获取锁对象
        SimpleRedisLock redisLock =new SimpleRedisLock(stringRedisTemplate);
        //尝试获取锁对象
        boolean isLock = redisLock.tryLock(1200);
        if(!isLock){
            return "获取锁失败";
        }
        Product product = productService.findByPid(productId);
        if(product.getStock()<seckillCount){
            return "库存不足";
        }
        product.setStock(product.getStock()-seckillCount);
        int row = productService.reduceInventory(product);
        if(row>0){
            //新增秒杀记录
            SeckillRecord record = new SeckillRecord();
            record.setPid(product.getPid());
            record.setCount(seckillCount);
            record.setPanme(product.getPname());
            record.setTime(new Timestamp(System.currentTimeMillis()));
            recodeService.save(record);
        }
        //释放锁
        redisLock.unlock();
        return "秒杀成功";
    }

server:
  port: 7000
spring:
  application:
    name: gateway-application
  cloud:
    nacos:
      discovery:
        server-addr: 127.0.0.1:8848
    gateway:
      discovery:
        locator:
          enabled: true
      routes:
        - id: reckill_route
          uri: lb://service-reckill
          order: 1
          predicates:
            - Path=/reckill-serv/**
          filters:
            - StripPrefix=1