11332 - Summing Digits - Java

 import java.io.BufferedReader;  
 import java.io.IOException;  
 import java.io.InputStream;  
 import java.io.InputStreamReader;  
 import java.util.StringTokenizer;  
 public class SummingDigits {  
      public static void main(String[] args) throws IOException {  
           Reader.init(System.in);  
           String line = "";  
           int sum;  
           while(!(line = Reader.next()).equals("0")) {  
                //System.out.println(line);  
                while(line.length() > 1) {  
                     sum = 0;  
                     for(int i = 0; i < line.length(); i++) {  
                          sum += (line.charAt(i) - '0');  
                          //System.out.println("DEBUG Sum = " + sum);  
                     }  
                     line = "" + sum;  
                }  
                System.out.println(line);  
           }  
      }  
 }  
 /** Class for buffered reading int and double values */  
 /** http://www.cpe.ku.ac.th/~jim/java-io.html */  
 class Reader {  
      static BufferedReader reader;  
      static StringTokenizer tokenizer;  
      /** call this method to initialize reader for InputStream */  
      static void init(InputStream input) {  
           reader = new BufferedReader(new InputStreamReader(input));  
           tokenizer = new StringTokenizer("");  
      }  
      /** get next word */  
      static String next() throws IOException {  
           while ( ! tokenizer.hasMoreTokens() ) {  
                //TODO add check for eof if necessary  
                tokenizer = new StringTokenizer(reader.readLine());  
           }  
           return tokenizer.nextToken();  
      }  
      static int nextInt() throws IOException {  
           return Integer.parseInt( next() );  
      }  
      static double nextDouble() throws IOException {  
           return Double.parseDouble( next() );  
      }  
 }