领域驱动设计(DDD):从基础代码探讨高内聚低耦合的演进【技术创作特训营第一期】

@Autowired
ProductDao productDao;
@Autowired
UserDao userDao;
public void createOrder(String productId,String userId,int count){
     Product product = productDao.queryById(productId);
     UserInfo user=userDao.queryByUserId(userId);
     
     //风控检测
     RiskResponse riskRes= riskClient.queryRisk(xxx);
     if(riskRes!=null&&riskRes.getCode()==0&&riskRes.getRiskCode().equal("0001")){
       //命中风控
          throw new BizException("下单失败，请检查网络")
     }
  
     Order order=new Order();
     order.setOrderId(IdUtils.generateId());
     order.setPrice(product.getPrice()*count);
     order.setAddress(user.getAddress());
     order.setStatus(OrderEnum.OrderSucess);
     orderDao.insert(order);
  
     //预热缓存和增加记录
     redisService.set("Order:OrderID_"+order.getOrderId(),order);
     orderLogDao.addLog(order);
       
      MessageEntity message = new MessageEntity();
      message.setOrderId(order.getOrderId());
      message.setMessage("下单成功");
      kafkaSender.sent(messageEntity);

}

riskRes!=null&&riskRes.getCode()==0&&(riskRes.getRiskCode().equal("0001")||riskRes.getRiskCode().equal("0002")||riskRes.getRiskCode().equal("0003"))，

order.setOrderId(IdUtils.generateId());
order.setPrice(product.getPrice() * count);

@Service
public class RiskCheckAdapter {
    @Autowired
    private RiskClient riskClient;
    public boolean isRiskDetected(String productId, String userId) {
        RiskResponse riskRes = riskClient.queryRisk(xxx); // 根据实际情况传入参数
        return riskRes != null && riskRes.getCode() == 0 && riskRes.getRiskCode().equals("0001");
    }
}

@Service
public class RiskCheckService {
    @Autowired
    private RiskCheckAdapter riskCheckAdapter;

    public boolean isRiskCheckPassed(String productId, String userId) {
        return riskCheckAdapter.isRiskDetected(productId, userId);
    }
}

// IProductRepository.java
public interface IProductRepository {
    Product findById(String productId);
}

// IUserRepository.java
public interface IUserRepository {
    User findByUserId(String userId);
}

// IOrderRepository.java
public interface IOrderRepository {
    Order add(OrderDO order);
}

// IOrderLogRepository.java
public interface IOrderLogRepository {
    void addLog(OrderLogDO log);
}

// ProductRepository.java
@Repository
public class  ProductRepository implements IProductRepository {
    @Autowired
    private ProductDao productDao;

    @Override
    public Product findById(String productId) {
        return productDao.queryById(productId);
    }
}

// UserRepository.java
@Repository
public class  UserRepository implements IUserRepository {
    @Autowired
    private UserDao userDao;
    @Override
    public User findByUserId(String userId) {
        return userDao.queryByUserId(userId);
    }
}

// UserRepository.java
@Repository
public class  OrderRepository implements IOrderRepository {
    @Autowired
    private OrderDao orderDao;
    @Autowired
    private OrderConvert orderConvert;
    @Override
    public int save(OrderDO order) {
        OrderPO orderPO=orderConvert.convertPO(order);
        return orderDao.insert(orderPO);
    }
}

// OrderLogRepository.java
@Repository
public class OrderLogRepository implements IOrderLogRepository {
    @Autowired
    private OrderLogDao orderLogDao;
    @Override
    public void addLog(OrderLog log) {
        orderLogDao.addLog(log);
    }
}

public class Order {
    private String orderId;
    private int count;
    private double totalPrice;
    private String address;
    private int status;

    public void createOrder(Product product, User user, int  count) {
        this.address = user.getAddress();
        this.status = OrderEnum.OrderSuccess;
        this.generateOrderId();
        this.calculateTotalPrice(product.getPrice(), count);
    }

    private void generateOrderId() {
        this.orderId = IdUtils.generateId();
    }

    private void calculateTotalPrice(double price, int count) {
        this.count = itemCount;
        this.totalPrice = price * count;
    }

    // ...其他属性和方法
}

public class OrderFactory {
    public static Order createOrder(Product product, User user, int itemCount) {
        Order order = new Order();
        order.createOrder(product, user, itemCount);
        return order;
    }
}

//使用方式 
Order order = orderFactory.createOrder(product, user, count);
orderDao.insert(order);

// CommonEventListener.java
@Service
public class CommonEventListener {

    @Autowired
    private IOrderLogRepository orderLogRepository;

    @Autowired
    private RedisService redisService;

    @Autowired
    private KafkaSender kafkaSender;

    @EventListener
    public void handleOrderCreatedEvent(OrderCreatedEvent event) {
        String orderId = event.getOrderId();
        Order order = getOrderDetailsFromRepository(orderId);

        // Process the event within the domain object
        order.processOrderCreatedEvent(orderLogRepository, redisService);
        sendMessage(order);
    }

    private Order getOrderDetailsFromRepository(String orderId) {
        // Retrieve order details from repository using orderId
        // Return the Order object
    }

    private void sendMessage(Order order) {
        MessageEntity message = new MessageEntity();
        message.setOrderId(order.getOrderId());
        message.setMessage("下单成功");
        kafkaSender.send(message);
    }
}

// OrderServiceImpl.java
@Service
public class OrderServiceImpl implements OrderService {
    @Autowired
    private ApplicationEventPublisher eventPublisher;
    @Autowired
    private IProductRepository productRepository;
    @Autowired
    private IUserRepository userRepository;
    @Autowired
    private IOrderRepository orderRepository;
    @Autowired
    private IOrderFactory orderFactory;
    @Autowired
    private RiskCheckService riskCheckService;

    @Override
    public Order createOrder(String productId, String userId, int count) {
        Product product = productRepository.findById(productId);
        User user = userRepository.findByUserId(userId);

        boolean isRiskPassed = riskCheckService.isRiskCheckPassed();

        if (!isRiskPassed) {
            throw new BizException("下单失败，请检查网络");
        }
      
        Order order = orderFactory.createOrder(product, user, count);
        orderRepository.save(order);

        // Publish OrderCreatedEvent
        eventPublisher.publishEvent(new OrderCreatedEvent(order.getOrderId()));
        return order;
    }
}