Java設計模式——策略模式

public interface Shape {
    public void outputShape();
}

class Circle implements Shape {
    public void outputShape() {
        System.out.println("this is a circle");
    }
}

class Square implements Shape {
    public void outputShape() {
        System.out.println("this is a square");
    }
}

class Triangle implements Shape {
    public void outputShape() {
        System.out.println("this is a triangle");
    }
}

public class Strategy {
    public static void strategic(Shape S) { 
        S.outputShape(); 
    }

    public static void main(String[] args) {
        strategic(new Circle());
        strategic(new Square());
        strategic(new Triangle());
    }
}