实验九

package 实验九;
import java.util.Scanner;
public class Point {
    static int x;
    static int y;
    Point(int x,int y){
        Point.x=x;
        Point.y=y;
    }
    @SuppressWarnings("serial")
    public static void main(String[] args) {
        try {
            @SuppressWarnings({ "unused", "resource" })
            Scanner shuru=new Scanner(System.in);
            System.out.println("请输入一个点:");
            int h=shuru.nextInt();
            int a=shuru.nextInt();
            @SuppressWarnings("unused")
            Point s=new Point(h,a);
            if(x>=0&&y>=0) {
                System.out.println("x为："+Point.x+"y为："+Point.y);
                }
            else {
                throw new Exception() {
                    public String toString() {
                        return "无效参数";
                    }
                };
            }
        }
        catch(Exception e){
            System.out.println(e.toString());
        }
        finally {
            System.out.println("程序结束");
        }
    }
}

package 实验九;

import java.util.Scanner;
public class Rectangle {
    static int length;
    static int width;
    public Rectangle(Point point1,int length,int width) throws IllegalArgumentException
    {
        Rectangle.length=length;
        Rectangle.width=width;
    }
    @SuppressWarnings("serial")
    public static void main(String[] args) {
        try {
            @SuppressWarnings("resource")
            Scanner shuru=new Scanner(System.in);
            System.out.println("请输入一个点:");
            int h=shuru.nextInt();
            int a=shuru.nextInt();
            System.out.println("请输入长方形的长:");
            int b=shuru.nextInt();
            System.out.println("请输入长方形的宽:");
            int c=shuru.nextInt();
            Point p1=new Point(h,a);
            @SuppressWarnings("unused")
            Rectangle m=new Rectangle(p1,b,c);
            if(length>0&&width>0) {
                System.out.println("这是一个长为"+Rectangle.length+"宽为"+Rectangle.width+"的长方形" );
                }
            else {
                throw new Exception() {
                    public String toString() {
                        return "无效参数";
                    }
                };
            }
        }
        catch(Exception e){
            System.out.println(e.toString());
        }
        finally {
            System.out.println("程序结束");
        }
    }
}

package 实验九;
import java.util.Scanner;
public class Triangle {
    @SuppressWarnings("unused")
    private static final Point Point = null;
    public Point point2,point3;
    protected double a,b,c;
    public Triangle(Point p1,Point p2,Point p3) //throws IllegalArgumentException
    {
        this.point2=p2;
        this.point3=p3;
    }
    public Triangle() {}
    @SuppressWarnings("serial")
    public static void main(String[] args) {
        try {
            @SuppressWarnings("resource")
            Scanner shuru=new Scanner(System.in);
            System.out.println("请输入一个点:");
            int h=shuru.nextInt();
            int a=shuru.nextInt();
            Point p1 = new Point(h,a);
            System.out.println("请输入一个点:");
            int h1=shuru.nextInt();
            int a1=shuru.nextInt();
            Point p2 = new Point(h1,a1);
            System.out.println("请输入一个点:");
            int h2=shuru.nextInt();
            int a2=shuru.nextInt();
            Point p3 = new Point(h2,a2);
            @SuppressWarnings("unused")
            Triangle s = new Triangle(p1, p2, p3);
            double g=(h1-h)/(a1-a);
            double p=(h2-h1)/(a2-a1);
            if(g!=p) {
                System.out.println("这三个点可以构成一个三角形");
            }
            else{
                throw new Exception() {
                    public String toString() {
                        return "无效参数";
                    }
                };
            }
        }
        catch(Exception e){
            System.out.println(e.toString());
        }
        finally {
            System.out.println("程序结束");
        }
    }
}

package 实验九;
import java.util.Scanner;
public class Polygon {
    Polygon(Point[] points) throws IllegalArgumentException
    {
        
    }
    @SuppressWarnings("serial")
    public static void main(String[] args) {
        @SuppressWarnings("resource")
        Scanner shuru=new Scanner(System.in);
        System.out.println("请输入n");
        int n=shuru.nextInt();
        int Point[]=new int[n];
        int i;
        for(i=0;i<n;i++) {
            System.out.println("请输入多边形的第"+i+"个点");
            int h1=shuru.nextInt();
            int a1=shuru.nextInt();
            @SuppressWarnings("unused")
            Point p2 = new Point(h1,a1);
        }
        try {
            if(Point.length>=3)
            {
                System.out.println("这可以构成一个多边形");
                }
            else {
                throw new Exception() {
                    public String toString() {
                        return "无效参数";
                    }
                };
            }
        }
        catch(Exception e){
            System.out.println(e.toString());
            }
        finally {
            System.out.println("程序结束");
        }
    }
}

通过本次实验了解了运行程序过程中出现的各种错误，针对不同的错误，采取不同的手段排除错误；理解了异常处理机制的运行方式；掌握了异常的抛出、捕获及处理方法；熟悉了自定义异常类的作用。