java - why is bufferedwriter not writing in the file?

Question

Here is the code snippet.

read = new FileReader("trainfiles/"+filenames[i]);
                br = new BufferedReader(read);
                while((lines = br.readLine())!=null){
                    st = new StringTokenizer(lines);
                    while(st.hasMoreTokens()){
                        bw = new BufferedWriter(new FileWriter("files/file.txt"));
                        bw.write(st.nextToken());
                        bw.newLine();
                    }
                }

Edit: I am reading files from a directory. So, I need to open the reader in every loop. I have made some modification, but then also it is not writing to that file. Here is the code:

for(i=0;i==0;i++){
            if(filenames[i].matches(".*ham.*")){
                System.out.println("ham:"+filenames[i]);
                read = new FileReader("trainfiles/"+filenames[i]);
                br = new BufferedReader(read);
                while((lines = br.readLine())!=null){
                    st = new StringTokenizer(lines);
                    while(st.hasMoreTokens()){
                        System.out.println(st.nextToken());
                       bw.write(st.nextToken());
                    }
                }
                bw.close();
                br.close();

            }else{
                System.out.println("spam:"+filenames[i]);
            }
                        }

edit: I modified the code, but no success,

while((lines = br.readLine())!=null){
                    st = new StringTokenizer(lines);
                    bw = new BufferedWriter(new FileWriter("files/file.txt"));
                    while(st.hasMoreTokens()){
                        System.out.println(st.nextToken());
                       bw.write(st.nextToken());
                    }
                    bw.close();
                }

                br.close();

And i am getting this error: Exception in thread "main" java.util.NoSuchElementException at java.util.StringTokenizer.nextToken(StringTokenizer.java:332) at Test.main(Test.java:30)

edit: Thanks guys.. I figured it out. Actually I created an directory in eclipse and I did not refresh it to see the content. Its silly... anyways.thanks a lot

Answer 1

A couple of things:

1. You're creating a new FileWriter each time through the loop, which will truncate the file each time.
2. BufferedWriter is buffered, and you're never flushing the buffer. You need to either call bw.flush(), or even better, close the writer when done.