@Autowired
private StockMapper stockMapper;
/**
* redisTemplate
*/
//StringRedisTemplate 和 RedisTemplate 序列化器不同
@Autowired
private StringRedisTemplate redisTemplate;
//redis的乐观锁保证了线程安全，但是效率比较慢，而且还会因为机器的性能问题，导致连接不够用，所以不推荐使用redis的的乐观锁
public void deduct() {
//加锁setnx
Boolean lockFirst = this.redisTemplate.opsForValue().setIfAbsent("lock", "111");
//
while(!lockFirst){
try {
Thread.sleep(50);
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
}
try {
// 1.查询库存信息
String stock = redisTemplate.opsForValue().get("stock").toString();
//2.判断库存是否充足
if (stock != null && stock.length() != 0) {
Integer st = Integer.valueOf(stock);
if (st > 0) {
//扣减库存
redisTemplate.opsForValue().set("stock", String.valueOf(--st));
}
}
} finally {
//解锁
this.redisTemplate.delete("lock");
}
}
