设计模式-原型模式

原型模式(Prototype Pattern)：

使用原型实例指定创建对象的种类，并且通过拷贝这些原型创建新的对象。原型模式是一种对象创建型模式

应用实例

描述如下：

未使用原型模式

#include<iostream>
#include<string>
#include<sstream>



using namespace std;


template<class T>
string ConvertToString(T value) {

	stringstream ss;
	ss << value;
	return ss.str();
}





class OrderApi {

public:

	virtual int getOrderNum() { return m_orderProductNum; };
	virtual void setOrderNum(int num) { m_orderProductNum = num; };
	virtual string getOrderContent() = 0;

protected:
	OrderApi() {};
	int m_orderProductNum;
};


class HomeOrder : public OrderApi {

public:
	
	
	virtual string getOrderContent() {
		
		return "客户是：" + m_customerName + "  订单的数量：" + ConvertToString<int>(m_orderProductNum) + "  订单id：" + m_productId;

	}

	void setCustomName(string name) {
		m_customerName = name;
	}

	string getCustomName() { return m_customerName; };


	void setId(string id) {
		m_productId = id;
	}

	string getId() { return m_productId; };

private:
	string m_customerName;
	string m_productId;
	
};




class AboardOrder : public OrderApi {

public:


	virtual string getOrderContent() {

		return "客户是：" + m_customerName + "  订单的数量：" + ConvertToString<int>(m_orderProductNum) + "  订单id：" + m_productId;

	}

	void setCustomName(string name) {
		m_customerName = name;
	}

	string getCustomName() { return m_customerName; };


	void setId(string id) {
		m_productId = id;
	}

	string getId() { return m_productId; };

private:
	string m_customerName;
	string m_productId;

};


class OrderBusiness {

public:
	void saveOrder(OrderApi* order);

};


void OrderBusiness::saveOrder(OrderApi* order) {

	while (order->getOrderNum() > 200)
	{
		OrderApi* neworder = nullptr;
		if (dynamic_cast<HomeOrder*>(order)!= nullptr)
		{
			HomeOrder* p2 = new HomeOrder;
			HomeOrder* p1 = static_cast<HomeOrder*>(order);
			p2->setOrderNum(200);
			p2->setCustomName(p1->getCustomName());
			p2->setId(p1->getId());
			neworder = p2;
		}

		if (dynamic_cast<AboardOrder*>(order) != nullptr)
		{
			HomeOrder* p2 = new HomeOrder;
			HomeOrder* p1 = static_cast<HomeOrder*>(order);
			p2->setOrderNum(200);
			p2->setCustomName(p1->getCustomName());
			p2->setId(p1->getId());
			neworder = p2;
		}

		//原来的订单更新数量
		order->setOrderNum(order->getOrderNum() - 200);
		cout << "New Order:" << neworder->getOrderContent() << endl;

	}

	cout << "Order:" << order->getOrderContent() << endl;

}

int main(void) {

	//system("killtask /m prototype.exe");
	
	HomeOrder* home = new HomeOrder();
	home->setOrderNum(512);
	home->setCustomName("zj");
	home->setId("c++");
	
	OrderBusiness* obj = new OrderBusiness;
	obj->saveOrder(home);
	
	
	return 0;
}

使用原型模式

#include<iostream>
#include<string>
#include<sstream>



using namespace std;


template<class T>
string ConvertToString(T value) {

	stringstream ss;
	ss << value;
	return ss.str();
}





class OrderApi {

public:

	virtual int getOrderNum() { return m_orderProductNum; };
	virtual void setOrderNum(int num) { m_orderProductNum = num; };
	virtual string getOrderContent() = 0;
	virtual OrderApi* cloneOrder() = 0;
protected:
	OrderApi() {};
	int m_orderProductNum;
};


class HomeOrder : public OrderApi {

public:


	virtual string getOrderContent() {

		return "客户是：" + m_customerName + "  订单的数量：" + ConvertToString<int>(m_orderProductNum) + "  订单id：" + m_productId;

	}

	void setCustomName(string name) {
		m_customerName = name;
	}

	string getCustomName() { return m_customerName; };


	void setId(string id) {
		m_productId = id;
	}

	string getId() { return m_productId; };

	virtual OrderApi* cloneOrder() {

		HomeOrder* p2 = new HomeOrder;
		p2->setOrderNum(200);
		p2->setCustomName(m_customerName);
		p2->setId(m_productId);
		return p2;
	}

private:
	string m_customerName;
	string m_productId;

};




class AboardOrder : public OrderApi {

public:


	virtual string getOrderContent() {

		return "客户是：" + m_customerName + "  订单的数量：" + ConvertToString<int>(m_orderProductNum) + "  订单id：" + m_productId;

	}

	void setCustomName(string name) {
		m_customerName = name;
	}

	string getCustomName() { return m_customerName; };


	void setId(string id) {
		m_productId = id;
	}

	string getId() { return m_productId; };

private:
	string m_customerName;
	string m_productId;

};


class OrderBusiness {

public:
	void saveOrder(OrderApi* order);

};


void OrderBusiness::saveOrder(OrderApi* order) {

	while (order->getOrderNum() > 200)
	{
		OrderApi* neworder = nullptr;
		if (dynamic_cast<HomeOrder*>(order) != nullptr)
		{
			HomeOrder* p2 = new HomeOrder;
			HomeOrder* p1 = static_cast<HomeOrder*>(order);
			p2->setOrderNum(200);
			p2->setCustomName(p1->getCustomName());
			p2->setId(p1->getId());
			neworder = p2;
		}

		if (dynamic_cast<AboardOrder*>(order) != nullptr)
		{
			HomeOrder* p2 = new HomeOrder;
			HomeOrder* p1 = static_cast<HomeOrder*>(order);
			p2->setOrderNum(200);
			p2->setCustomName(p1->getCustomName());
			p2->setId(p1->getId());
			neworder = p2;
		}

		//原来的订单更新数量
		order->setOrderNum(order->getOrderNum() - 200);
		cout << "New Order:" << neworder->getOrderContent() << endl;

	}

	cout << "Order:" << order->getOrderContent() << endl;

}

int main(void) {

	//system("KILLTASK /M Prototype.exe");

	HomeOrder* home = new HomeOrder();
	home->setOrderNum(512);
	home->setCustomName("ZJ");
	home->setId("C++");

	OrderBusiness* obj = new OrderBusiness;
	obj->saveOrder(home);


	return 0;
}

总结