Java抽象工厂模式

抽象工厂模式是一个超级工厂，用来创建其他工厂。 这个工厂也被称为工厂的工厂。 这种类型的设计模式属于创建模式，因为此模式提供了创建对象的最佳方法之一。

在抽象工厂模式中，接口负责创建相关对象的工厂，而不明确指定它们的类。 每个生成的工厂可以按照工厂模式提供对象。

下面是AbstractFactoryPattern Java Code

package com.milo.patterns;

/**
 * step 1:创建Shape的接口。
 * 
 * @author MILO
 *
 */
interface Shape {
	void draw();
}

/**
 * step 2:创建实现相同接口的具体类
 * 
 * @author MILO
 *
 */
class Rectangle implements Shape {
	@Override
	public void draw() {
		System.out.println("Inside Rectangle::draw() method.");
	}
}

class Square implements Shape {
	@Override
	public void draw() {
		System.out.println("Inside Square::draw() method.");
	}
}

class Circle implements Shape {
	@Override
	public void draw() {
		System.out.println("Inside Circle::draw() method.");
	}
}

/**
 * step 3:创建一个Colors接口，如下所示
 * 
 * @author MILO
 *
 */
interface Color {
	void fill();
}

/**
 * step 4:创建实现相同接口的具体类
 * 
 * @author MILO
 *
 */
class Red implements Color {
	@Override
	public void fill() {
		System.out.println("Inside Red::fill() method.");
	}
}

class Green implements Color {
	@Override
	public void fill() {
		System.out.println("Inside Green::fill() method.");
	}
}

class Blue implements Color {
	@Override
	public void fill() {
		System.out.println("Inside Blue::fill() method.");
	}
}

/**
 * step 5:创建实现相同接口的具体类
 * 
 * @author MILO
 *
 */
abstract class AbstractFactory {
	abstract Color getColor(String color);

	abstract Shape getShape(String shape);
}

/**
 * step 6:创建实现相同接口的具体类
 * 
 * @author MILO
 *
 */
class ShapeFactory extends AbstractFactory {
	@Override
	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;
	}
}

class ColorFactory extends AbstractFactory {

	@Override
	public Shape getShape(String shapeType) {
		return null;
	}

	@Override
	Color getColor(String color) {

		if (color == null) {
			return null;
		}

		if (color.equalsIgnoreCase("RED")) {
			return new Red();

		} else if (color.equalsIgnoreCase("GREEN")) {
			return new Green();

		} else if (color.equalsIgnoreCase("BLUE")) {
			return new Blue();
		}

		return null;
	}
}

/**
 * step 7:创建工厂生成器/生产器类，通过传递如Shape或Color等信息来获取工厂
 * 
 * @author MILO
 *
 */
class FactoryProducer {
	public static AbstractFactory getFactory(String choice) {
		if (choice.equalsIgnoreCase("SHAPE")) {
			return new ShapeFactory();

		} else if (choice.equalsIgnoreCase("COLOR")) {
			return new ColorFactory();
		}
		return null;
	}
}
/**
 * step 8:使用FactoryProducer来获取AbstractFactory，以便通过传递类型等信息来获取具体类的工厂。
 * @author MILO
 *
 */
public class AbstractFactoryPatternDemo {
	 public static void main(String[] args) {

	      //get shape factory
	      AbstractFactory shapeFactory = FactoryProducer.getFactory("SHAPE");

	      //get an object of Shape Circle
	      Shape shape1 = shapeFactory.getShape("CIRCLE");

	      //call draw method of Shape Circle
	      shape1.draw();

	      //get an object of Shape Rectangle
	      Shape shape2 = shapeFactory.getShape("RECTANGLE");

	      //call draw method of Shape Rectangle
	      shape2.draw();

	      //get an object of Shape Square 
	      Shape shape3 = shapeFactory.getShape("SQUARE");

	      //call draw method of Shape Square
	      shape3.draw();

	      //get color factory
	      AbstractFactory colorFactory = FactoryProducer.getFactory("COLOR");

	      //get an object of Color Red
	      Color color1 = colorFactory.getColor("RED");

	      //call fill method of Red
	      color1.fill();

	      //get an object of Color Green
	      Color color2 = colorFactory.getColor("Green");

	      //call fill method of Green
	      color2.fill();

	      //get an object of Color Blue
	      Color color3 = colorFactory.getColor("BLUE");

	      //call fill method of Color Blue
	      color3.fill();
	   }
	}

验证输出结果如下：

Inside Circle::draw() method.
Inside Rectangle::draw() method.
Inside Square::draw() method.
Inside Red::fill() method.
Inside Green::fill() method.
Inside Blue::fill() method.

摘录于--------《易百教程》