抽象工厂模式(对象创建)

#include <iostream>#include <string>using namespace std;//工厂模式：客户类和工厂类分开。//消费者任何时候需要某种产品，只需向工厂请求即可。//消费者无须修改就可以接纳新产品。缺点是当产品修改时，//工厂类也要做相应的修改。如：如何创建及如何向客户端提供。//消费者不固定，工厂者不固定，（工厂根据消费者动作）//实现消费者抽象基类，消费者派生类的实现，实例化就是消费者//操作的抽象基类，实现派生类各种操作，实例化的操作//工厂的抽象类，抽象类包含了两个抽象类的接口（消费者，操作）//抽象类实现了工厂类的抽象，实例化的派生类，实现工厂，//根据用户设置用户，根据操作设置操作class IUser{public:virtual void getUser() = 0;  //纯虚接口类，抽象类virtual void setUser() = 0;};class SqlUser :public IUser   //继承抽象实现sql数据库使用者的实例化{public:void getUser(){cout << "在sql中返回user" << endl;}void setUser(){cout << "在sql中设置user" << endl;}};class AccessUser :public IUser //继承抽象实现access数据库使用者的实例化{public:void getUser(){cout << "在Access中返回user" << endl;}void setUser(){cout << "在Access中设置user" << endl;}};class IDepartment  //抽象类，提供接口{public:virtual void getDepartment() = 0;virtual void setDepartment() = 0;};class SqlDepartment :public IDepartment  //SQL操作的实现{public:void getDepartment(){cout << "在sql中返回Department" << endl;}void setDepartment(){cout << "在sql中设置Department" << endl;}};class AccessDepartment :public IDepartment //access操作的实现{public:void getDepartment(){cout << "在Access中返回Department" << endl;}void setDepartment(){cout << "在Access中设置Department" << endl;}};class IFactory     //抽象工厂{public:virtual IUser *createUser() = 0;virtual IDepartment *createDepartment() = 0;};class SqlFactory :public IFactory  //抽象工厂一个实现{public:IUser *createUser(){return new SqlUser();}IDepartment *createDepartment(){return new SqlDepartment();}};class AccessFactory :public IFactory // 抽象工厂一个实现{public:IUser *createUser(){return new AccessUser();}IDepartment *createDepartment(){return new AccessDepartment();}};/*************************************************************///变相的实现了静态类class DataAccess{private:static string db;//string db="access";public:static IUser *createUser(){if (db == "access"){return new AccessUser();}else if (db == "sql"){return new SqlUser();}}static IDepartment *createDepartment(){if (db == "access"){return new AccessDepartment();}else if (db == "sql"){return new SqlDepartment();}}};string DataAccess::db = "sql";int main(){//IFactory *factory=new SqlFactory();IFactory *factory;//抽象工厂IUser *user;//抽象消费者IDepartment *department;//提供的操作factory = new AccessFactory();//基类的指针指指向派生类的对象user = factory->createUser();//基类的指针指向派生类的对象department = factory->createDepartment();//基类的指针指向派生类的对象user->getUser();user->setUser();//访问acesss接口department->getDepartment();department->setDepartment();//接口user = DataAccess::createUser();department = DataAccess::createDepartment();user->getUser();user->setUser();department->getDepartment();department->setDepartment();cin.get();return 0;}