public static void main(String arg[])  
    {
        new TestStreamTokenizer().testInOut(arg[0], arg[1]);
    }
 
 
private void createReadWriteStreams(String inFName, String outFName) 
{
            _fileReader = new FileReader(inFName);
            _fileWriter = new FileWriter(outFName);
            _printWriter = new PrintWriter(_fileWriter);
}
 
 public void testInOut(String inFName, String outFName) 
{
            createReadWriteStreams(inFName, outFName);
             StreamTokenizer tokenizer = new    StreamTokenizer(_fileReader);
            tokenizer.eolIsSignificant(true);
 
            int nextTok = tokenizer.nextToken();
 
            while (StreamTokenizer.TT_EOF != nextTok) 
            {
                // ........................
                //I don't know how can I do it???
 
            }
}

BufferedReader reader = new BufferedReader(new FileReader("foo.in"));
String inputString = reader.readLine();
 
// strip out the stuff you don't want
String cleanString = inputString.replaceAll("<P ID=\\d+>", "");
cleanString = cleanString.replaceAll("<P>", "");
cleanString = cleanString.replaceAll("[IVXLCDM]+\\.", "");
 
// get the remaining words into an array
String[] words = cleanString.split(" ");
 
// loop words and write them, then read next line, etc.