Lettura Token Funzionante

import java.io.*;
import java.util.*;
/*Con file TXT del tipo:
A:B:C
D:E:F
G:H:I
L:M:N*/

    public class LetturaconTokenizer {

        public static void main (String[] args) {
            try {
              FileReader f = null;

                f=new FileReader("prova.txt");

                BufferedReader b;
                b = new BufferedReader(f);

                String lettura;

                while ((lettura = b.readLine()) != null)
                {
                    StringTokenizer st = new StringTokenizer(lettura, ":");

                while (st.hasMoreTokens())
                {
                   String A = st.nextElement().toString();
                   String B = st.nextElement().toString();
                   String C = st.nextElement().toString();
                   System.out.println(A);
                   System.out.println(B);
                   System.out.println(C);


                }

            }
            b.close();
            } catch(Exception e) {  //???
                        e.printStackTrace(); //???
                }
            }
        }