Mine

import java.util.*;
import java.io.*;
import java.util.regex.*;
public class CountWords
{
    private File file;
    private ArrayList<Word> words;
    public CountWords(String fileName)
    {
       this(new File(fileName));
    }
    public CountWords(File file)
    {
        this.file = file;
        words = new ArrayList<Word>();
        try 
        {
            BufferedReader in = new BufferedReader(new FileReader(file));
            String str = "";
            String line;
            while((line = in.readLine())!= null)
                str += line + " ";
            str = str.toLowerCase(); // Word matching is case insensitive
            in.close();
            Pattern wordPattern = Pattern.compile("[a-z-]+");
            Matcher matcher = wordPattern.matcher(str);
            while(matcher.find())
            {
                String word = str.substring(matcher.start(), matcher.end());
                if(!(word.equals("null") || word.equals("-"))) // If the word is not "-" or "null"
                {
                    int index = inArray(word);
                    if(index != -1) // If the current word is in the words ArrayList
                        words.get(index).addCount();
                    else // Otherwise add new word
                        words.add(new Word(word));
                }
            }
            Collections.sort(words);
        } 
        catch (IOException e) 
        {
            e.printStackTrace();
        }
    }
    public int numWords()
    {
        int sum = 0;
        for(int i = 0; i < words.size(); i++)
            sum += words.get(i).getCount();
        return sum;
    }
    
    public void printTopWords(int n)
    {
        System.out.println("Unique Words: " + words.size());
        System.out.println("Word Count: " + numWords());
        for(int i = 0; i < n; i++)
            System.out.println(i + ". " + words.get(i).getWord() + " - " + words.get(i).getCount());
    }
    public void printTopWords()
    {
        printTopWords(20);
    }
    
    private int inArray(String word)
    {
        for(int i = 0; i < words.size(); i++)
            if(word.equals(words.get(i).getWord()))
                return i;
        return -1;
    }  
}