以下程序运行完之后想再继续做题需要再运行。怎么做到重复出题，按某一健才不出题那

以下程序运行完之后想再继续做题需要再运行。如何做到重复出题，按某一健才不出题那
import java.util.Random;
import java.util.Scanner;
public class JiaFa 
{
int a;
  int b;
  int sum;
  public int JiaF()
   
  {
  Random random = new Random();
  this.a = random.nextInt(10);
  this.b = random.nextInt(10);
  System.out.println(a + "+" + b+ "=");
  return sum = a + b;
 
}
  public void showTitle()
  {
  System.out.println("请计算此题目：");
  }

public static void main(String[] args) 
{  
JiaFa he = new JiaFa();
 
he.showTitle();
he.JiaF();
Scanner sc = new Scanner(System.in);
int c = sc.nextInt();

if( he.sum == c)
{
System.out.println("正确。");
}
else
{
System.out.println("错误，正确答案为： " + he.sum );
}

  }
}


------解决方案--------------------------------------------------------
输入q后按回车退出

Java code

    public static void main(String[] args) {        JiaFa he = new JiaFa();        Scanner sc = new Scanner(System.in);        while (true) {            he.showTitle();            he.JiaF();            int c;            try {                c = sc.nextInt();                if (he.sum == c) {                    System.out.println("正确。");                } else {                    System.out.println("错误，正确答案为： " + he.sum);                }            } catch (InputMismatchException e) {                String s = sc.nextLine();                if (s.equals("q"))                    break;            }        }    }