private static void emptyFile(File logFile) {
        BufferedWriter out = null;
        try {
            out = new BufferedWriter(new FileWriter(logFile));
            out.write("");
        } catch (IOException ex) {
            Logger.warn("Could not empty file " + logFile.getName(), ex);
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (IOException ex) {
                    Logger.warn("Could not close file.", ex);
                }
            }
        }
    }
Returns the directory that log files exist in. The directory name will
have a File.separator as the last character in the string.

@return the directory that log files exist in.
xmppserver/src/main/java/org/jivesoftware/util/Log.java