三角形圆形矩形 部分程序: //TriangleException.java public class TriangleException extends Exception{ double baseA,baseB,baseC; TriangleException(double baseA,double baseB
duck的java程序 //duck.java public abstract class Duck { FlyBehavior flyBehavior; QuackBehavior quackBehavior; public Duck(){ } public abstract void display(); public