OUTPUT OF TOKENS TO FILE

Question

Okay, I have a program which reads in a file, the contents of this file are then tokenized. I have a method to determine whether to keep the token or not. If I want to keep the token I write it to another file. But that is where my problem is. Each useful token just overwrites the last one and so the file only stores the last token. Is there a way that I can append to this file rather than overwrite each time. Here is my code:
import java.util.*;
import java.io.*;
import java.util.Enumeration;
public class Token
public static String buf;
     public static void tokenize(String file4Format)
     StringTokenizer parser;
     String token;
     String tk2;
          try
               BufferedReader in = new BufferedReader(new FileReader(file4Format));
               String s;
               while ((s=in.readLine())!=null)
               parser= new StringTokenizer(s);
               while (parser.hasMoreTokens())
                    token = (String)parser.nextToken();
                    token = token.toLowerCase();
                    token = token.replace(',',' ');
                    token = token.replace('.',' ');
                    token = token.replace(';',' ');
                    token = token.replace(':',' ');
System.out.println("token="+token);
IrrelevantWords stopWordList = new IrrelevantWords();     
          IrrelevantWords.storage();
BufferedWriter out2 = new BufferedWriter(new FileWriter("useful.txt"));
          //this call to determine if token in hashtable
if (!stopWordList.isElement(token))
          out2.write(token);                     out2.flush();
          out2.close();
          else
          System.out.println(" in list" +token);
          }catch(IOException e)//while//while
     }

Answer 1

try flushing and closing your file AFTER you completely finish writing. As of now you are writing a line and then flushing the buffer and closing the file. Then when you read in the next line you are writing it to the beginning again.