Factory mothed pattern-factory method mode

Factory mothed pattern, called factory method mode

First, let's take a look at how gof defines the factory method mode:

"Define an interface for creating an object, but let subclasses decide which class to instantiate. Factory method lets a class defer Instantiation to subclasses."-gof

"Define an interface to create an object and let the subclass decide which class to instantiate. The factory method mode delays the class Instantiation to the subclass"-gof

Abstract Factory(Abstractfactory):Is the core of the factory method model. The specific factory must implement the abstract method defined in the abstract factory.

Specific Factory(Concretefactory):Implement all the abstract methods defined in the abstract factory, including the logic closely related to the business.

Abstract Product(Abstractproduct):Super category of all specific products, that is, the common parent category of specific products.

Specific products(Concreteproduct):This role implements the interface defined by the abstract Product role.

In C ++, the C ++ polymorphism is actually used. Instance: A factory produces Mercedes-Benz cars, a factory generates Audi cars, and tests are required.

 1   Class  Car  2   {  3       Public  :  4          Virtual   Void Run () = 0  ;  5   };  6   7   Class Audicar: Public  Car  8   { 9       Public  :  10           Void  Run ();  11   };  12   Void  Audicar: Run ()  13   { 14 STD: cout < "  Audi is running  " < STD: Endl;  15   }  16   17   Class Benzcar: Public  Car 18   {  19       Public  :  20           Void  Run ();  21   }  22   Void  Benzcar: Run () 23   {  24 STD: cout < "  Benz is running  " < STD: Endl;  25   };  26   27   Class Carfactory  28   {  29       Public  :  30          Virtual Car * createcar () = 0  ;  31   };  32  33   Class Audicarfactory: Public  Carfactory  34   {  35       Public  :  36 Car * Createcar ();  37  };  38 Car * Audicarfactory: createcar ()  39   {  40           Return   New  Audicar ();  41   }  42   43  Class Benzcarfactory: Public  Carfactory  44   {  45       Public  :  46 Car * Createcar ();  47   }; 48 Car * Benzcarfactory: createcar ()  49   {  50           Return   New  Benzcar ();  51   }  52   53   Void Createandtest (carfactory * P)  54   {  55 Car * c = p-> Createcar ();  56 C-> Run ();  57   Delete C;  58   }  59  60   Int Main ( Int Argc, Char * Argv)  61   {  62 Carfactory * P1 = New Benzcarfactory (); //  The subclass determines the object to be instantiated. 63 Carfactory * P2 = New  Audicarfactory ();  64   Createandtest (P1 );  65   Createandtest (P2 );  66   Delete P1;  67   Delete P2;  68      Return   0  ;  69 }

 

 
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