作用:
提供一個創(chuàng)建一系列相關(guān)或相互依賴對象的接口，而無需指定它們具體的類。
UML結(jié)構(gòu)圖:
抽象基類:
1)ProductA,ProductB:分別代表不同類型的產(chǎn)品,而它們的派生類則是這種產(chǎn)品的一個實現(xiàn).
2)AbstractFactory:生產(chǎn)這一系列產(chǎn)品的一個抽象工廠,它的派生類是不同的實現(xiàn).
接口函數(shù):
1)AbstractFactory::CreateProductA和AbstractFactory::CreateProductB:分別是生產(chǎn)不同產(chǎn)品的不同的實現(xiàn),由各個派生出來的抽象工廠實現(xiàn)之.
解析:
Abstract Factory模式和Factory最大的差別就是抽象工廠創(chuàng)建的是一系列相關(guān)的對象,其中創(chuàng)建的實現(xiàn)其實采用的就是Factory模式的方法,對于某個實現(xiàn)的有一個派生出來的抽象工廠,另一個實現(xiàn)有另一個派生出來的工廠,等等.
可以舉一個簡單的例子來解釋這個模式:比如,同樣是雞腿(ProductA)和漢堡(ProductB),它們都可以有商店出售(AbstractFactory),但是有不同的實現(xiàn),有肯德基(ConcreateFactory1)和麥當(dāng)勞(ConcreateFactory2)兩家生產(chǎn)出來的不同風(fēng)味的雞腿和漢堡(也就是ProductA和ProductB的不同實現(xiàn)).
而負(fù)責(zé)生產(chǎn)漢堡和雞腿的就是之前提過的Factory模式了.
抽象工廠需要特別注意的地方就是區(qū)分不同類型的產(chǎn)品和這些產(chǎn)品的不同實現(xiàn).顯而易見的,如果有n種產(chǎn)品同時有m中不同的實現(xiàn),那么根據(jù)乘法原理可知有n*m個Factory模式的使用.
實現(xiàn):
1)AbstractFactory.h
/**//********************************************************************
????created:????2006/07/19
????filename:?????AbstractFactory.h
????author:????????李創(chuàng)
????????????????http://m.shnenglu.com/converse/
????purpose:????AbstractFactory的演示代碼
*********************************************************************/
#ifndef?ABSTRACTFACTORY_H
#define?ABSTRACTFACTORY_H
//?抽象基類AbstractProductA,代表產(chǎn)品A的抽象
class?AbstractProductA
{
public:
????AbstractProductA()?{}
????virtual?~AbstractProductA(){};
};
//?派生類ConcreateProductA1,繼承自AbstractProductA,代表產(chǎn)品A的第一種實現(xiàn)
class?ConcreateProductA1
????:?public?AbstractProductA
{
public:
????ConcreateProductA1();
????virtual?~ConcreateProductA1();
};
//?派生類ConcreateProductA2,繼承自AbstractProductA,代表產(chǎn)品A的第二種實現(xiàn)
class?ConcreateProductA2
????:?public?AbstractProductA
{
public:
????ConcreateProductA2();
????virtual?~ConcreateProductA2();
};
//?抽象基類AbstractProductB,代表產(chǎn)品B的抽象
class?AbstractProductB
{
public:
????AbstractProductB()?{}
????virtual?~AbstractProductB(){};
};
//?派生類ConcreateProductB1,繼承自AbstractProductB,代表產(chǎn)品B的第一種實現(xiàn)
class?ConcreateProductB1
????:?public?AbstractProductB
{
public:
????ConcreateProductB1();
????virtual?~ConcreateProductB1();
};
//?派生類ConcreateProductB2,繼承自AbstractProductB,代表產(chǎn)品B的第二種實現(xiàn)
class?ConcreateProductB2
????:?public?AbstractProductB
{
public:
????ConcreateProductB2();
????virtual?~ConcreateProductB2();
};
//?抽象基類AbstractFactory,工廠的抽象類,生產(chǎn)產(chǎn)品A和產(chǎn)品B
class?AbstractFactory
{
public:
????AbstractFactory(){}
????virtual?~AbstractFactory(){}
????virtual?AbstractProductA*?CreateProductA()?=?0;
????virtual?AbstractProductB*?CreateProductB()?=?0;
};
//?派生類ConcreateFactory1,繼承自AbstractFactory
//?生產(chǎn)產(chǎn)品A和產(chǎn)品B的第一種實現(xiàn)
class?ConcreateFactory1
????:?public?AbstractFactory
{
public:
????ConcreateFactory1();
????virtual?~ConcreateFactory1();
????virtual?AbstractProductA*?CreateProductA();
????virtual?AbstractProductB*?CreateProductB();
};
//?派生類ConcreateFactory2,繼承自AbstractFactory
//?生產(chǎn)產(chǎn)品A和產(chǎn)品B的第二種實現(xiàn)
class?ConcreateFactory2
????:?public?AbstractFactory
{
public:
????ConcreateFactory2();
????virtual?~ConcreateFactory2();
????virtual?AbstractProductA*?CreateProductA();
????virtual?AbstractProductB*?CreateProductB();
};
#endif2)AbstractFactory.cpp
/**//********************************************************************
????created:????2006/07/19
????filename:?????AbstractFactory.cpp
????author:????????李創(chuàng)
????????????????http://m.shnenglu.com/converse/
????purpose:????AbstractFactory的演示代碼
*********************************************************************/
#include?<iostream>
#include?"AbstractFactory.h"
ConcreateProductA1::ConcreateProductA1()
{
????std::cout?<<?"construction?of?ConcreateProductA1\n";
}
ConcreateProductA1::~ConcreateProductA1()
{
????std::cout?<<?"destruction?of?ConcreateProductA1\n";
}
ConcreateProductA2::ConcreateProductA2()
{
????std::cout?<<?"construction?of?ConcreateProductA2\n";
}
ConcreateProductA2::~ConcreateProductA2()
{
????std::cout?<<?"destruction?of?ConcreateProductA2\n";
}
ConcreateProductB1::ConcreateProductB1()
{
????std::cout?<<?"construction?of?ConcreateProductB1\n";
}
ConcreateProductB1::~ConcreateProductB1()
{
????std::cout?<<?"destruction?of?ConcreateProductB1\n";
}
ConcreateProductB2::ConcreateProductB2()
{
????std::cout?<<?"construction?of?ConcreateProductB2\n";
}
ConcreateProductB2::~ConcreateProductB2()
{
????std::cout?<<?"destruction?of?ConcreateProductB2\n";
}
ConcreateFactory1::ConcreateFactory1()
{
????std::cout?<<?"construction?of?ConcreateFactory1\n";
}
ConcreateFactory1::~ConcreateFactory1()
{
????std::cout?<<?"destruction?of?ConcreateFactory1\n";
}
AbstractProductA*?ConcreateFactory1::CreateProductA()
{
????return?new?ConcreateProductA1();
}
AbstractProductB*?ConcreateFactory1::CreateProductB()
{
????return?new?ConcreateProductB1();
}
ConcreateFactory2::ConcreateFactory2()
{
????std::cout?<<?"construction?of?ConcreateFactory2\n";
}
ConcreateFactory2::~ConcreateFactory2()
{
????std::cout?<<?"destruction?of?ConcreateFactory2\n";
}
AbstractProductA*?ConcreateFactory2::CreateProductA()
{
????return?new?ConcreateProductA2();
}
AbstractProductB*?ConcreateFactory2::CreateProductB()
{
????return?new?ConcreateProductB2();
} 3)Main.cpp(測試代碼)
/**//********************************************************************
????created:????2006/07/19
????filename:?????Main.cpp
????author:????????李創(chuàng)
????????????????http://m.shnenglu.com/converse/
????purpose:????AbstractFactory的測試代碼
*********************************************************************/
#include?"AbstractFactory.h"
#include?<stdlib.h>
int?main()
{
????//?生產(chǎn)產(chǎn)品A的第一種實現(xiàn)
????ConcreateFactory1?*pFactory1?=?new?ConcreateFactory1;
????AbstractProductA?*pProductA?=?pFactory1->CreateProductA();
????//?生產(chǎn)產(chǎn)品B的第二種實現(xiàn)
????ConcreateFactory2?*pFactory2?=?new?ConcreateFactory2;
????AbstractProductB?*pProductB?=?pFactory2->CreateProductB();
????delete?pFactory1;
????delete?pProductA;
????delete?pFactory2;
????delete?pProductB;
????system("pause");
????return?0;
}