• 生产者完成创建订单和扣减库存之后，发送消息到延迟队列。

// 3.清理购物车商品cartClient.deleteCartItemByIds(itemIds);// cartService.removeByItemIds(itemIds);// 4.扣减库存try {itemClient.deductStock(detailDTOS);//itemService.deductStock(detailDTOS);} catch (Exception e) {throw new RuntimeException("库存不足！");}// 5.TODO发送延迟消息，检查用户是否已经支付完成rabbitTemplate.convertAndSend(MQConstants.DELAY_EXCHANGE_NAME,MQConstants.DELAY_ORDER_KEY,order.getId(),message -> {message.getMessageProperties().setDelay(10000);return message;});

• 消费者监听消息，先查订单状态，没支付在查支付信息。

@Slf4j
@Component
@AllArgsConstructor
public class OrderDelayMessageListener {private final IOrderService orderService;private final PayClient payClient;@RabbitListener(bindings = @QueueBinding(value = @Queue(name = MQConstants.DELAY_ORDER_QUEUE_NAME),exchange = @Exchange(name = MQConstants.DELAY_EXCHANGE_NAME, delayed = "true"),key = MQConstants.DELAY_ORDER_KEY))public void listenOrderDelayMessage(Long orderId) {// 1.查询订单状态Order order = orderService.getById(orderId);// 2.检测订单状态，判断是否已支付if(order == null || order.getStatus()!=1) {log.info("delayMQ：用户已支付订单【{}】",orderId);return;}// 3.未支付，查询订单流水PayOrderDTO payOrder = payClient.queryPayOrderByBizOrderNo(orderId);// 4.判断是否支付if (payOrder == null || payOrder.getStatus() == 3) {// 4.1 已支付，标记订单状态已支付orderService.markOrderPaySuccess(orderId);log.info("delayMQ：已更新订单【{}】",orderId);} else {// 4.2 未支付，取消订单，恢复库存orderService.cancelOrder(orderId);log.info("delayMQ：已取消订单【{}】",orderId);}}
}