Java求乘积小问题

我知道可以用循环但是第一次就输入0怎么让他直接结束啊，怎么写他都会输出1

public static void main(String args[]) {
        
        System.out.println("请输入一串数字，以空格分割");
        Scanner sc = new Scanner(System.in);
        String str = sc.nextLine();
        String[] numArr = str.split(" ");
        int sum = 0;
        for(int i=0; i<numArr.length -1; i++) {
            int num = Integer.parseInt(numArr[i]);
            if(sum == 0) {
                sum = num;
            }else {
                sum = sum * num;
            }
        }
        System.out.println("结果为：" + sum);
        
    }

public class Test05 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String next = scanner.nextLine();
        String[] s = next.split("\\s+");
        int res = 1;
        if (s.length-1>10) {
            System.out.println("最多输入10个整数");
        }else {
            for (int i = 0; i < s.length - 1; i++) {
                res=res*Integer.valueOf(s[i]);
            }
        }
        System.out.println("乘积是"+res);

    }
}