How to extract unique words in all files

Question

Hi,
I am trying to extract all the UNIQUE words of all the files in a directory. well it gives me all the words but along with that all the single letters(alphabets and also repetitions of the same ) and also the output is not unique. I dont want the alphabets only unique words in the files. [Like for example if I encounter file x with words "cat mat sat" and then file y with words "cat mat bat pat". My output should be "cat mat sat bat pat"]
Can you please let me know what is used to get the unique words only? Or how I can modify my code to get the desired output...
//String input = "Input text, with words, punctuation, etc. Well, it's rather short.";
               Pattern p = Pattern.compile("[\\w']+",Pattern.MULTILINE);
               FileInputStream fis = new FileInputStream(file);
             FileChannel fc = fis.getChannel();
             ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, (int)fc.size());
             Charset cs = Charset.forName("8859_1");
             CharsetDecoder cd = cs.newDecoder();
             CharBuffer cb = cd.decode(bb);
             // Run some matches
             Matcher m = p.matcher(cb);
               while ( m.find() ) {
                   //System.out.println(cb.substring(m.start(), m.end()));
                   System.out.println(m.group());
                Thanks

Answer 1

Can you tell me how to add the contents of a file into a set?
   import java.io.*;
import java.util.*;
public class RmDup{
     public static void main(String args[]){
               FileReader fr = new FileReader("Dups.txt");
               BufferedReader br = new BufferedReader(fr);
               String s1[]=br.readLine();
               String s2;
               while ((s2=br.readLine())!=null){
                HashSet ref = new HashSet( s1 ); // create a HashSet
                Iterator i = ref.iterator(); // get iterator
                System.out.println( "\nNonduplicates are: " );
                while ( i.hasNext() )
                     System.out.print( i.next() + " " );
                System.out.println();
}I am trying using this: but getting errors 1: incompatible types and 2:cannot find symbol constructor HashSet(java.lang.String[]).
Thanks