Sum of digits of a number in java

Java code to add all digits of a numbers

import java.io.*;



class Test {

public static void main(String[] args) throws IOException {



int num,sum=0,r;

System.out.println("Enter a number:");

BufferedReader br=new BufferedReader(new InputStreamReader (System.in));

num=Integer.parseInt(br.readLine());



while(num!=0){