实验九：异常的抛出、捕获并处理

 1 package error;
 2 
 3 public class Throwerror {
 4 public static void main(String[] args) throws IllegalArgumentException
 5 {    Point point1=new Point (3,1);
 6      Point point2=new Point (6,2);
 7      Point point3=new Point (9,3);
 8      new Rectangle(point1, -12,3);
 9      new Triangle(point1,point2,point3);
10      Point[] point= {point1,point2};
11      new Polygon(point);
12     }
13 
14 }
15 
16 class Point
17 {   public Point() {};
18     public int x;
19     public int y;
20     public Point(int x,int y)
21    {   this.x=x;
22        this.y=y;
23         
24         if(x<0||y<0)
25             throw new IllegalArgumentException("Point中无效参数异常");
26        }
27     }
28 class Rectangle extends Point
29 {
30     public int length,width;
31     public Rectangle(Point point1,int length,int width) {
32         this.length=length;
33         this.width=width;
34         if(length<0||width<0)
35             throw new IllegalArgumentException("Rectangle无效参数异常");
36     }
37     }
38 class Triangle extends Point 
39 {
40     
41     public Triangle(Point point1,Point point2,Point point3) {
42         if(point1.x/point1.y==point2.x/point2.y&&point2.x/point2.y==point3.x/point3.y)
43             throw new IllegalArgumentException("Triangle无效参数异常");
44         }
45     }
46 
47 class Polygon extends Point
48 {   int i=0;
49     public Polygon(Point[] points)
50     { i=points.length;
51       if(i<=2)
52         throw new IllegalArgumentException("Polygon无效参数异常");
53         }
54 
55     }
56