public static void main(String[] args) {
    BigDecimal a = new BigDecimal(22);
    a = a.divide(new BigDecimal(7), 100,BigDecimal.ROUND_HALF_UP);
    System.out.println(a);
  }

------解决方案--------------------
Java code
public class Test {
    public static void main(String[] args) {
        System.out.println(div7(22, 100));  // 22/7 的第 100 位
        System.out.println(div7(33, 100));  // 33/7 的第 100 位
    }

    public static int div7(int numerator, int digit) {          
        int mod = numerator % 7;
        if(mod == 0) {
            return 0;
        }
        String repetend = "142857";
        int[] shift = {0, 2, 1, 4, 5, 3};
        char c = repetend.charAt((digit + shift[mod - 1] - 1) % 6);
        return c - '0';
    }
}