Java Count Word Occurrences

import java.util.*;
class  CountWordOccurences{
    public static TreeMap count(String str){
        TreeMap<String, Integer> map = new TreeMap<String, Integer>();
        str = str.toLowerCase();
    StringTokenizer stk = new StringTokenizer(str, " \t\n\r\f.,;:!?'");
    while (stk.hasMoreTokens()) {
    String word = stk.nextToken();
    Integer frequency = map.get(word);
    if (frequency == null) {
    frequency = 0;
    }
    map.put(word, frequency + 1);
    }
    return map;
    }

    public static void main(String[] args){
    String st="Where there is will, there is a way";
    TreeMap<String, Integer> map = count(st);
    Set set = map.entrySet();
    Iterator i = set.iterator();
    while(i.hasNext()) {
    Map.Entry m = (Map.Entry)i.next();
    System.out.print(m.getKey() + "\t:\t ");
    System.out.println(m.getValue());
     } 
    }
}