private static FileLogger getFileLogger() {
   if (fileLogger == null) {
     fileLogger = new FileLogger("log.txt");
   }
   File file = fileLogger.getFile();
   if (file.length() > (1024 * 1000)) {
     SimpleDateFormat dateFormat = new SimpleDateFormat("yyyyMMddhhmmss");
     Date now = Calendar.getInstance().getTime();
     String fileName = String.format("log%s.txt", dateFormat.format(now));
     file.renameTo(new File(fileName));
     fileLogger = new FileLogger("log.txt");
   }
   return fileLogger;
 }