下单流程解耦新方案-你知道Spring事件监听机制吗

// 1. 自定义订单事件
public class OrderEvent extends ApplicationEvent {
...
}
// 2. 定义订单监听器
@Component
public class OrderListener implements ApplicationListener<OrderEvent> {
    @Override
    public void onApplicationEvent(OrderEvent event) {
    // 生成订单、删除购物车、扣减库存
    ...
    }
}
// 3. 通过 applicationEventPublisher 发布事件
@Resource
private ApplicationEventPublisher applicationEventPublisher;
private void saveOrder(MallUserVO mallUserVO, Long couponUserId, List<ShopCatVO> shopcatVOList, String orderNo) {
    // 订单检查
   ...
    // 生成订单号
    String orderNo = NumberUtil.genOrderNo();
    // 发布订单事件，在事件监听中处理下单逻辑
    applicationEventPublisher.publishEvent(new OrderEvent(orderNo, mallUserVO, couponUserId, shopcatVOList));
    // 所有操作成功后，将订单号返回
    return orderNo;
    ...
}

/**
 * 系统启动时執行
 */
@Component
public class SpringBeanStartupRunner implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        // 设置 spring 默认的事件监听为异步执行
        SimpleApplicationEventMulticaster multicaster = SpringContextUtil.getBean(SimpleApplicationEventMulticaster.class);
        ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(
                5,
                10,
                60L, TimeUnit.MILLISECONDS,
                new LinkedBlockingQueue<>(500),
                new CustomizableThreadFactory("newbee—event-task"),
                new ThreadPoolExecutor.CallerRunsPolicy()
        );
        multicaster.setTaskExecutor(threadPoolExecutor);
    }
}