@Service
public class OrderService {
    @Autowired private InventoryService inventoryService;
    @Autowired private UserService userService;
    @Autowired private MailService mailService;
    @Autowired private LogService logService;


    public void createOrder(Order order) {
        orderRepository.save(order);
        System.out.println("訂單創(chuàng)建成功：" + order.getId());


        try {
            inventoryService.decreaseStock(order.getProductId(), order.getQuantity());
            userService.addPoints(order.getUserId(), 100);
            mailService.sendMail(order.getUserId(), "訂單成功", "感謝購(gòu)買");
            logService.logAction("CREATE_ORDER", order.getId());
        } catch (Exception e) {
            logger.error("后續(xù)操作失敗", e);
        }
    }
}

package com.icoderoad.order.event;


import com.icoderoad.order.model.Order;
import org.springframework.context.ApplicationEvent;


public class OrderCreatedEvent extends ApplicationEvent {
    private final Order order;


    public OrderCreatedEvent(Object source, Order order) {
        super(source);
        this.order = order;
    }


    public Order getOrder() {
        return order;
    }
}

@Service
public class OrderService {


    private final ApplicationEventPublisher eventPublisher;


    @Autowired
    public OrderService(ApplicationEventPublisher eventPublisher) {
        this.eventPublisher = eventPublisher;
    }


    public void createOrder(Order order) {
        // 核心邏輯：保存訂單
        orderRepository.save(order);
        System.out.println("訂單創(chuàng)建成功：" + order.getId());


        // 發(fā)布事件
        OrderCreatedEvent event = new OrderCreatedEvent(this, order);
        eventPublisher.publishEvent(event);
        System.out.println("已廣播訂單創(chuàng)建事件");
    }
}

/com/icoderoad/inventory/InventoryListener.java
/com/icoderoad/user/UserListener.java
/com/icoderoad/logging/LogListener.java
/com/icoderoad/notification/MailListener.java
@Component
public class InventoryListener {
    @Async
    @EventListener
    public void onOrderCreated(OrderCreatedEvent event) {
        System.out.println("【庫(kù)存服務(wù)】處理訂單：" + event.getOrder().getId());
    }
}
@Component
public class UserListener {
    @EventListener
    public void onOrderCreated(OrderCreatedEvent event) {
        System.out.println("【用戶服務(wù)】添加積分：" + event.getOrder().getUserId());
    }
}
@Component
public class MailListener {
    @EventListener
    public void onOrderCreated(OrderCreatedEvent event) {
        System.out.println("【郵件服務(wù)】發(fā)送確認(rèn)郵件：" + event.getOrder().getUserId());
    }
}
@Component
public class LogListener {
    @EventListener
    public void onOrderCreated(OrderCreatedEvent event) {
        System.out.println("【日志服務(wù)】記錄訂單操作日志：" + event.getOrder().getId());
    }
}