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;
}