源代码：
package yichang;
public class Yichang {
public static void main(String[] args) {
point p1=new point(1,3);
point p2=new point(1,2);
point p3=new point(1,1);
new rectangle(p1,-2,6);
new triangle(p1,p2,p3);
point[] point= {p1,p2};
new Polygon(point);
}
}
class point {
public int x,y;
public point() {}
public point(int x,int y)throws IllegalArgumentException
{
this.x=x;
this.y=y;
if(x<0||y<0)
throw new IllegalArgumentException("无效参数");
}
}
class rectangle extends point{
public int width,length;
public rectangle(point point1,int length,int width)throws IllegalArgumentException
{
this.length=length;
this.width=width;
if(length<0||width<0)
throw new IllegalArgumentException("参数无效");
}
}
class triangle extends point{
public triangle(point point1,point point2,point point3)throws IllegalArgumentException
{
if(((point1.x-point2.y)-(point2.x-point1.y))+((point2.x-point3.y)-(point3.x-point2.y))+((point3.x-point1.y)-(point3.y-point1.x))==0)
throw new IllegalArgumentException("无效的参数");
}
}
class Polygon extends point
{ int i=0;
public Polygon(point[] points)
{ i=points.length;
if(i<=2)
throw new IllegalArgumentException("Polygon无效参数异常");
}
}
结果：
Exception in thread "main" java.lang.IllegalArgumentException: 参数无效
at yichang.rectangle.<init>(Yichang.java:40)
at yichang.Yichang.main(Yichang.java:12)
心得体会：
通过本次实验我学习到了异常的抛出，捕获，并处理。但在具体输出中还是有些错误，但在同学帮助下理解了异常处理。