Question

这是我正在使用的程序，需要4个int并找到它们的区域。我需要设置一个Exception来检测用户是否没有输入int和字符串。我希望它告诉用户（“仅限数字”）

stdate <= enddate

我有点想法就像这里一样..

package areacircle;
import java.util.Scanner;
public class AreaCircleTwoPointO {

public static void main(String[] args) {
Scanner reader = new Scanner (System.in);
    System.out.print ("Type The x1 point please: ");
    int x1 = reader.nextInt();
    System.out.print ("Type The x2 point please: ");
    int x2 = reader.nextInt();
    System.out.print ("Type The y1 point please: ");
    int y1 = reader.nextInt();
    System.out.print ("Type the y2 point please: ");
    int y2 = reader.nextInt();
    double area = areaCircle(x1, x2, y1, y2);
    System.out.println ("The area of your circle is: " + area);
}
    public static double distance
           (double x1, double y1, double x2, double y2)
{
    double dx = x2 - x1;
    double dy = y2 - y1;
    double dsquared = dx*dx + dy*dy;
    double result = Math.sqrt (dsquared);
    return result;
}

public static double areaCircle(double x1, double y1, double x2, double y2)
{
    double secretSauce = distance(x1, y1, x2, y2);
    return areaCircleOG(secretSauce);
}

public static double areaCircleOG(double secretSauce)
{
    double area = Math.PI * Math.pow(secretSauce, 2);
    return area;
}
}

但关于这一点的是它正在使用JOptionPane而我不想使用JOptionPane，只是扫描仪。

Answer 1

您可以使用以下代码：

public static void main(String[] args) 
{
    Scanner reader = new Scanner (System.in);

    boolean finished = false;
    while(!finished)
    {
        try
        {
            System.out.print ("Type The x1 point please: ");
            int x1 = reader.nextInt();
            System.out.print ("Type The x2 point please: ");
            int x2 = reader.nextInt();
            System.out.print ("Type The y1 point please: ");
            int y1 = reader.nextInt();
            System.out.print ("Type the y2 point please: ");
            int y2 = reader.nextInt();
            double area = areaCircle(x1, x2, y1, y2);
            System.out.println ("The area of your circle is: " + area);
            double area = areaCircle(x1, x2, y1, y2);
            System.out.println ("The area of your circle is: " + area);
            finished = true;
        }
        catch(NumberFormatException e)
        {
            System.out.println("Please type in a number! Try again.");
        }
    } 
}

我将如何处理此程序中的异常？

1 个答案: