工廠模式&&抽象工廠模式

2.抽象工廠模式 和 工廠模式對比

簡單來說，抽象工廠模式正如名字所示，即對工廠進行抽象，比起工廠模式多了一層抽象而已。在《Design Pattern Explains》書中，作者說的很到位，設計模式即是“Find what varies and encapsulate it”, 翻譯過來即 封裝起那些變換的事物。

如下所示(圖引用於here)：抽象工廠模式中把 產生A，B的工廠，抽象成一個 類，類中通過方法來產生有關聯的產品，比如圓形，方形。而每個方法，都是依賴工廠模式實現

CODE 1: Factory Pattern

public interface Shape{
  void draw();
}
public class Rectangle implements Shape{
  public void draw(){
   System.out.println("Inside Square::draw() method.");
  }
}
public class CircleimplementsShape{
   public void draw(){
   Systerm.out.println("Inside Circle::draw() method");
 }
}
public class ShapeFactory{
   public shape getShape (String shapeType){
      if(shapeType == null){
          return  null;
        }
       if(shapeType.equalsIgnoreCase("CIRCLE")){
        return new Circle(); 
      }else if(ShapeType.equalsIgnoreCase("RECTANGLE")){
         return new Rectangle();
      }else if(ShapeType.equalsIgnoreCase("SQUARE")){
         return new Square();
       }
      return null;
    }
}
// client code
  public class FactoryPatternDemo{
    public static void main(String[] args){
     ShapeFactory shapeFactory = new ShapeFactory();
     Shape shape1 = shapeFactory.getShape("CIRCLE");
     shape1.draw();
     Shape shape2 = shapeFactory.getShape("RECTANGLE");
     shape2.draw();
     Shape shape3 = shapeFactory.getShape("SQUARE");
     shape3.draw();
     }
 }

CODE2: ABSTRACT Fatory PAttern

public interface Shape{
  void draw();
}
public class Rectangle implements Shape{
  public void draw(){
   System.out.println("Inside Square::draw() method.");
  }
}
public class Circle implements Shape{
   public void draw(){
   Systerm.out.println("Inside Circle::draw() method");
 }
}
public interface <span style="color:#cc0000;">Color</span>{
  void draw();
}
public class Red implements Color{
  public void draw(){
   System.out.println("Inside Red::fill() method.");
  }
}
public class Green implements Color{
   public void draw(){
   Systerm.out.println("Inside Green::fill() method");
 }
}
public abstract class AbstractFactory{
 abstract Color getColor(String color);
 abstract Shape getShape(String shape);
}
public class ShapeFactory extends AbstractFactory{
   public shape getShape(String shapeType){
      if(shapeType == null){
          return  null;
        }
       if(shapeType.equalsIgnoreCase("CIRCLE")){
        return new Circle(); 
      }else if(ShapeType.equalsIgnoreCase("RECTANGLE")){
         return new Rectangle();
      }else if(ShapeType.equalsIgnoreCase("SQUARE")){
         return new Square();
       }
      return null;
    }
   // override
   Color getColor(String color){
     return null;
    }
}
public class  ColorFactory extends AbstractFactory{
//override 
  public Shape getShape(String shapeType){
    return null;
   }
    Color getColor(String color){
    if(color == null){
     return null;
   }   
     if(color.equalsIgnoreCase("RED")){
       return new Red();
     }else if(color.equalsIgnoreCase("Green")){
       return new Green();
     }
   }
}

public class FactoryProducer{
   public static AbstractFactory getFactory(String chioce){
   if(choice.equalsIgnoreCase("SHAPE")){
       return new ShapeFactory();
    }else if(choice.equalsIgnoreCase("COLOR")){
      return new ColorFactory();
    }
    return null;
 }
}