public class Test3 {public  static void main(String[] args) throws ParseException {ArrayList<Integer> list=new ArrayList<>();Scanner sc=new Scanner(System.in);while (true){System.out.println("请输入一个整数");String s = sc.nextLine();int i = Integer.parseInt(s);if(i<1||i>100){System.out.println("请重新输入一个数");continue;}list.add(i);int sum = getSum(list);if(sum>200){System.out.println("和大于两百");break;}}}private static int getSum(ArrayList<Integer> list) {int sum=0;for (int i = 0; i < list.size(); i++) {int i1 = list.get(i);sum=sum+i1;}return sum;}}

自己把字符串转化成整数：

public class Test3 {public  static void main(String[] args) throws ParseException {String str="123456789";if(!str.matches("[1-9]\\d{0,9}")){System.out.println("数据格式有误");}else {System.out.println("数据格式正确");}int number=0;for (int i = 0; i < str.length(); i++) {int c = str.charAt(i);int s=c-'0';number=number*10+s;}System.out.println(number);}}