Java program to sum digits of a number.

package demo;
import java.util.Scanner;
public class SumOfDigits
{
 public static void main(String[] args) 
 {
  Scanner sc = new Scanner(System.in);
  int num, sum = 0, r;
  System.out.println("Enter a number: ");
  num = sc.nextInt();
  while (num != 0) {
   r = num % 10;
   num = num / 10;
   sum = sum + r;
  }
  System.out.print("Sum of digits of number:  " + sum);
 }
}

Output:
Enter a number: 32165
Sum of digits of number:  17
BUILD SUCCESSFUL (total time: 8 seconds)