创建型模式-抽象工厂模式

在抽象工厂模式中，接口是负责创建一个相关对象的工厂，不需要显式指定它们的类。每个生成的工厂都能按照工厂模式提供对象。
抽象工厂模式提供了一种创建一系列相关或相互依赖对象的接口，而无需指定具体实现类。通过使用抽象工厂模式，可以将客户端与具体产品的创建过程解耦，使得客户端可以通过工厂接口来创建一族产品。

意图：提供一个创建一系列相关或相互依赖对象的接口，而无需指定它们具体的类。
主要解决：主要解决接口选择的问题。
何时使用：系统的产品有多于一个的产品族，而系统只消费其中某一族的产品。
如何解决：在一个产品族里面，定义多个产品。

public interface Shape {void draw();
}public class Circle implements Shape{@Overridepublic void draw() {System.out.println("this is Circle");}
}public class Rectangle implements Shape{@Overridepublic void draw() {System.out.println("this is Rectangle");}
}public class Square implements Shape {@Overridepublic void draw() {System.out.println("this is Square");}
}

public interface Color {void fill();
}public class Blue implements Color{@Overridepublic void fill() {System.out.println("this is blue");}
}public class Green implements Color{@Overridepublic void fill() {System.out.println("this is green");}
}public class Red implements Color{@Overridepublic void fill() {System.out.println("this is red");}
}

public  abstract class AbstractFactory {public abstract Color getColor(String color);public abstract Shape getShape(String shape);
}

public class ColorFactory extends AbstractFactory{@Overridepublic 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;}@Overridepublic Shape getShape(String shape) {return null;}
}

public class ShapeFactory extends AbstractFactory{@Overridepublic Color getColor(String color) {return null;}public Shape getShape(String shapeType){if (shapeType == null){return null;}if (shapeType.equalsIgnoreCase("CIRCLE")){return new Circle();}if (shapeType.equalsIgnoreCase("RECTANGLE")){return new Rectangle();}if (shapeType.equalsIgnoreCase("SQUARE")){return new Square();}return null;}
}

public 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;}
}

   @Testpublic void test7(){AbstractFactory shapeFactory = FactoryProducer.getFactory("SHAPE");Shape shape1 = shapeFactory.getShape("CIRCLE");shape1.draw();Shape shape2 = shapeFactory.getShape("RECTANGLE");shape2.draw();Shape shape3 = shapeFactory.getShape("SQUARE");shape3.draw();AbstractFactory colorFactory = FactoryProducer.getFactory("COLOR");Color color1 = colorFactory.getColor("RED");color1.fill();Color color2 = colorFactory.getColor("GREEN");color2.fill();Color color3 = colorFactory.getColor("BLUE");color3.fill();}
/**
this is Circle
this is Rectangle
this is Square
this is red
this is green
this is blue
**/