Create a design pattern (a) factory method pattern

First, a word background

I need a car, I can pick up from inside the factory directly, without having to pipe the car is how to do it, as well as the production of concrete realization of the car, I just need to tell what brand of car like this factory to produce specific I do not have auto production line pipe.

Second, the use of scenarios

We know some characteristics and create specific object scene.

As: according to the type of environment (dev, test, or master, etc.) directly call set environment configuration

Third, the model analysis

Production lines: interface defines the methods of production of cars

Specific product production lines: class, inside methods to help us create a concrete class object (car), production line interface specific implementation

Factory: class, according to different customer needs to call the assembly line production of cars 

Fourth, code analysis

Production lines

/ ** 
 * Create a production line interface methods defined automobile production 
 * / 
public  interface CarProductionLine {
     // The method of producing an automobile 
    void produceCar (); 
}

 

Various brands of automobile production lines (product-specific production lines)

/ ** 
 * BMW production line 
 * / 
public  class BmwProductionLine the implements CarProductionLine { 

    @Override 
    public  void produceCar () {
         // A method to achieve the production line defined by the interface, producing BMW 
        System.out.println ( "BMW is opened and the whole - " ); 
    } 
}

/ ** 
 * Mercedes production line 
 * / 
public  class BenzProductionLine the implements CarProductionLine { 

    @Override 
    public  void produceCar () {
         // A method to achieve the production line defined by the interface, producing Mercedes 
        System.out.println ( "Benz opened and the whole ~ " ); 
    } 
}

/ ** 
 * Audi production line 
 * / 
public  class AudiProductionLine the implements CarProductionLine { 

    @Override 
    public  void produceCar () {
         // A method to achieve the production line defined by the interface, producing Audi 
        System.out.println ( "Audi opened and the whole ~ " ); 
    } 
}

 

factory

/ ** 
 * automobile manufacturing plant 
 * / 
public  class CarFactory { 

    // use getCar method call different production lines 
    public CarProductionLine getCar (String carBrand) {
         IF (carBrand == null ) {
             return  null ; 
        } 
        IF (carBrand.equalsIgnoreCase ( "BMW " )) {
             return  new new BmwProductionLine (); 
        } the else  IF (carBrand.equalsIgnoreCase (" Benz " )) {
             return  new new BenzProductionLine (); 
        } the else  IF (carBrand.equalsIgnoreCase("audi")) {
            return new AudiProductionLine();
        }
        return null;
    }
    
}

 

Customer orders

public  class ConsumerOrderDemo { 
 
   public  static  void main (String [] args) { 
      CarFactory carFactory = new new CarFactory (); 
 
      // customer to buy a BMW, the factory get the object BmwProductionLine and call it getCar method 
      ProductionLine bmwProductionLine = carFactory.getCar ( "bmw " ); 
 
      // call produceCar method BmwProductionLine of 
      bmwProductionLine.produceCar ();
 

　　　 // customer to buy the Mercedes-Benz factory get the object BenzProductionLine and call it getCar method 
    　ProductionLine benzProductionLine = carFactory.getCar ( "Benz" ); 
 
      // call produceCar method BenzProductionLine of 
      benzProductionLine.produceCar ();

      // Audi customers want to buy, factory get the object AudiProductionLine and call it getCar method 
      ProductionLine audiProductionLine = carFactory.getCar ( "Audi" ); 
 
      // call produceCar method AudiProductionLine of 
      audiProductionLine.produceCar ();

} }