Java-- 类型信息

　　不想写文字啊！

package typeinfo;

import java.util.*;

abstract class Shape{
    void draw(){ System.out.println(this + ".draw()");}
    abstract public String toString();
}

class Circle extends Shape{
    public String toString(){
        return "Circle";
    }
}

class Square extends Shape{
    public String toString(){
        return "Square";
    }
}

class Triangle extends Shape{
    public String toString(){
        return "Triangle";
    }
}


public class Shapes {
    public static void main(String [] args){
        List<Shape>  shapelist = Arrays.asList(
                new Circle(), new Square(),new Triangle());
        for(Shape shape:shapelist)
            shape.draw();
    }
}

结果：

Circle.draw()
Square.draw()
Triangle.draw()