抽象工厂模式

#include <iostream>
#include <string>
using namespace std;

class IUser
{
public:
    virtual void getUser()=0;
    virtual void setUser()=0;
};

class SqlUser:public IUser
{
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
{
public:
    void getUser()
    {
        cout<<"在Access中返回user"<<endl;
    }
    void setUser()
    {
        cout<<"在Access中设置user"<<endl;
    }
};


class IDepartment
{
public:
    virtual void getDepartment()=0;
    virtual void setDepartment()=0;
};

class SqlDepartment:public IDepartment
{
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
{
public:
    void getDepartment()
    {
        cout<<"在Access中返回Department"<<endl;
    }
    void setDepartment()
    {
        cout<<"在Access中设置Department"<<endl;
    }
};

class IFactory
{
public:
    virtual IUser *createUser()=0;
    virtual IDepartment *createDepartment()=0;
};

class SqlFactory:public IFactory
{
public:
    IUser *createUser() 
    {
        return new SqlUser();
    }
    IDepartment *createDepartment() 
    {
        return new SqlDepartment();
    }
};

class AccessFactory:public IFactory
{
public:
    IUser *createUser()
    {
        return new AccessUser();
    }
    IDepartment *createDepartment() 
    {
        return new AccessDepartment();
    }
};

/*************************************************************/

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;
    IUser *user;
    IDepartment *department;

    factory=new AccessFactory();
    user=factory->createUser();
    department=factory->createDepartment();

    user->getUser();
    user->setUser();
    department->getDepartment();
    department->setDepartment();


    user=DataAccess::createUser();
    department=DataAccess::createDepartment();

    user->getUser();
    user->setUser();
    department->getDepartment();
    department->setDepartment();




    return 0;
}

GOOD：定义了一个创建一系列相关或相互依赖的接口，而无需指定它们的具体
类。
用于交换产品系列，如 ACCESS­>SQL SERVER；
产品的具体类名被具体工厂的实现分离