FileReader fr = new FileReader(name_of_file);
BufferedReader br = new BufferedReader(fr);

String s;

while((s = br.readLine()) != null){

s = s.replace(".", " ").replace("'", " ").replace(",", " ").replace("(", " ").replace(")", " ").replace("?", " ".replace("!", " ");

String [] words = s.split("\\s+");


for(int i=0; i<words.length; i++)
    if(words[i].length()>0)
        addToTree(words[i]);


}