用java编写数字8759各个位数字逐步相加最后加到一位数

public class Test {

  public static void main(String[] args) {
    int num = 8759;
    int sum = 0;

    while (num > 10) {
      sum = 0;
      while (num > 0) {
        sum += num % 10;
        num = num / 10;
      }
      num = sum;
      System.out.println(num);
    }
  }
}

public class Test {

public static void main(String[] args) {
String num="8752";

while(num.length()>1){
int sum=0;
char[] c=num.toCharArray();
for(char cc:c){
sum+=Integer.parseInt(cc+"");
num