import java.util.InputMismatchException;import java.util.Scanner;public class MyTest { public static void main(String[] args) { System.out.println("请输入一个数："); Scanner input = new Scanner(System.in); int num = 0; try { num = input.nextInt(); } catch (InputMismatchException ime) { System.out.println("输入的不是一个数字！"); } int result = 0; for (int i = 0; i <= num; i++) { result += i; } System.out.println("结果是:" + result); }}