DDD 中具有独立的领域模型和持久性模型

DDD 中的领域模型和持久性模型

java
// 领域模型
public class Order {
    private String orderId;
    private List items;
    public Order(String orderId, List items) {
        this.orderId = orderId;
        this.items = items;
    }
    // ...其他业务方法和领域规则
}
public class OrderItem {
    private String itemId;
    private String name;
    private int quantity;
    public OrderItem(String itemId, String name, int quantity) {
        this.itemId = itemId;
        this.name = name;
        this.quantity = quantity;
    }
    // ...其他业务方法和领域规则
}
// 持久性模型
public interface OrderRepository {
    void save(Order order);
    Order findById(String orderId);
    void delete(String orderId);
}
public class InMemoryOrderRepository implements OrderRepository {
    private Map orders = new HashMap<>();
    @Override
    public void save(Order order) {
        orders.put(order.getOrderId(), order);
    }
    @Override
    public Order findById(String orderId) {
        return orders.get(orderId);
    }
    @Override
    public void delete(String orderId) {
        orders.remove(orderId);
    }
}
// 使用示例
public class Main {
    public static void main(String[] args) {
        OrderRepository repository = new InMemoryOrderRepository();
        List items = new ArrayList<>();
        items.add(new OrderItem("1", "item1", 2));
        items.add(new OrderItem("2", "item2", 1));
        Order order = new Order("1234", items);
        repository.save(order);
        Order retrievedOrder = repository.findById("1234");
        System.out.println(retrievedOrder);
        repository.delete("1234");
    }
}