What is the easiest way to delete a line in a file?

Question

Hi!
I have a file that is line oriented. I am using BufferedReader and BufferedWriter. My problem is, is how do I easily delet a line from a file? Sort of like this:
This
is
not
a
file
To:
This
is
a
file
My file then has to be resaved like that.

Answer 1

That was my idea what you did. Just making sure their
was no other way. There are surely other ways to do it.
As the file is dynamic, I have no
Idea how many lines long it is. Thank you.But you have not just an idea but the exact size of file!
That's just an example:import java.io.*;
class X {
     private static final String BAD_LINE = "so bad!";
     private static final String NEW_LINE = System.getProperty("line.separator");
     public static void main(String[] args) throws IOException {
          File f = new File("filename");
          //supposing in "worst" scenario nothing will be removed
          StringBuffer sb = new StringBuffer((int)f.length());
          String line = "";
          BufferedReader in = new BufferedReader(new FileReader(f));
          while((line = in.readLine()) != null) {
               //just filter out good lines
               if(!line.equals(BAD_LINE)) sb.append(line + NEW_LINE);
          in.close();
          //write back the processed file:
          BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("filename"));
          byte[] bout = sb.toString().getBytes();
          out.write(bout, 0, bout.length);
          out.close();