Appending to a log file

Question

I have a custom log file. It is for a client/server app, (so the application keeps running indefinitely). I output lots of data to this file. I was wondering what the best way is to do this.
- 1) keep the log file open indefinitely and just keep writing to it. Lots of data is sent, so I should not keep opening and closing it.
- 2) Keep opening and closing it as needed, so the file does not become locked.
- 3) Keep some kind of buffer and when it reaches a certain size, open and close the file. But this may be tricky since the app runs indefinitely, If an error occurs somewhere, or the app hangs, I may have something in the buffer that didn't get written to a file.
- 4) ??
public void writeToFile(String text)
try
   PrintWriter out = new PrintWriter(
     new BufferedWriter(new FileWriter("theFile.txt", true))
   out.println(text); // append text to the end of the file
   out.close();
catch (IOException e)
   System.err.println(e.toString());
}or
public void alreadyOpen(String text)
  out.println( text );
  out.flush();

Answer 1

Hmmm ok that's weird. I didn't try FTP though on a folder where a log file could be, but by opening it through the standard Windows file explorer it works fine.
So maybe FTP is trying to get a lock on a file whenever you try to open it, even in read-only mode, which looks bad... Maybe there's some configuration to be done on your FTP client ?
In that case you're kind of stuck, you have to release the lock each time.
OR you could write the logs each time in a temporary file, and then copy the contents to the "accessible through FTP" file once/twice a day or the like. But still you wouldn't be able to see what's going on in the log file at realtime...
Well, that FTP constraint puzzles me.