c++设计模式之抽象工厂模式

/************************************************************************//*                           抽象工厂模式                               *//************************************************************************//*抽象工厂模式简介:一个工厂接口，多个产品接口这里我们以数据库的维护为例，假设现在有一个工程项目不一定会用到Access和SqlServer这两种数据库的哪一种，但是此工程中数据库的相关表已经被定下因为对Access和Sqlserver的操作并不相同，此时为了维护方便我们可以使用抽象工厂模式*//*假如现在的工程中存在两个表User和Deparment*/#include <IOSTREAM>using namespace std;/*用户*/class User{};/*部门*/class Department{};//定义User表的抽象接口class IUser{public://向Iuser表中插入一个uservirtual void Insert(User* user) = 0;virtual User* GetUser(int id) = 0;//根据id获取user};//Access中的User表(具体)class AccessUser : public IUser{public:void Insert(User *user){cout<<"在Access数据库中的IUser表中插入一个User(记录)"<<endl;}User* GetUser(int id){cout<<"从Access数据库的IUser表中根据id获取一条记录"<<endl;return NULL;}};class SqlserverUser : public IUser{public:void Insert(User *user){cout<<"在Sqlserver数据库中的IUser表中插入一个User(记录)"<<endl;}User* GetUser(int id){cout<<"从Sqlserver数据库的IUser表中根据id获取一条记录"<<endl;return NULL;}};//定义Deparment表的抽象接口class IDepartment{public:virtual void Insert(Department *department) = 0;virtual Department *GetDepartment(int id) = 0;};//Access 数据库中的Department表class AccessDepartment : public IDepartment{public:void Insert(Department* department){cout<<"在Access数据库的IDepartment表中插入一条记录"<<endl;}Department* GetDepartment(int id){cout<<"从Access数据库的IDepartment表根据id获取一条记录"<<endl;return NULL;}};//Sqlserver数据库中的Department表class SqlserverDepartment : public IDepartment{public:void Insert(Department* department){cout<<"在Sqlserver数据库的IDepartment表中插入一条记录"<<endl;}Department* GetDepartment(int id){cout<<"从Sqlserver数据库的IDepartment表根据id获取一条记录"<<endl;return NULL;}};//工厂接口class IFactory{public:virtual IUser * CreateUser() = 0;virtual IDepartment *CreateDepartment() = 0;};//Access工厂类class AccessFactory : public IFactory{public:IUser* CreateUser(){return new AccessUser();}IDepartment* CreateDepartment(){return new AccessDepartment();}};//sqlserver工厂类class SqlserverFactory : public IFactory{public:IUser* CreateUser(){return new SqlserverUser();}IDepartment* CreateDepartment(){return new SqlserverDepartment();}};void main(){//建立一个Access工厂IFactory *sqlserverFactory = new SqlserverFactory();IUser *user = sqlserverFactory->CreateUser();user->Insert(new User());user->GetUser(0);/*使用这种设计模式的好处是，1.当你需要更换数据库或时只需要更改一个地方2.当你需要对其他表进行操作时也只需要改一个地方  可维护性大大提高*/}

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