public class Ocp {
    public static void main(String[] args) {
        //使用看看存在的问题
        GraphicEditor graphicEditor = new GraphicEditor();
        graphicEditor.drawShape(new Rectangle());
        graphicEditor.drawShape(new Circle());
    }
}
//这是一个用于绘图的类[使用方]
class GraphicEditor{
    //接收shape对象,根据type，来绘制不同的图形
    public void drawShape(Shape s){
        if (s.m_type == 1){
            drawRectangle(s);
        }else if(s.m_type == 2){
            drawCircle(s);
        }
    }
    public void drawRectangle(Shape r){
        System.out.println("矩形");
    }
    public void drawCircle(Shape r){
        System.out.println("圆形");
    } 
}
//[提供方]
class Shape{
    int m_type;
}
class Rectangle extends Shape{
    Rectangle(){
        super.m_type = 1;
    }
}
class Circle extends Shape{
    Circle(){
        super.m_type = 2;
    }
}