code: public void delete(String fileName) {
  		try {
  			synchronized (prepareAnchor(fileName)) {
  				// Close file, if it was opened
  				IoChannel fileChannel = openFiles.remove(fileName);
  				if (fileChannel != null)
  					fileChannel.close();
  
  				// Delete the file
  				boolean hasDeleted = new File(dbDirectory, fileName).delete();
  				if (!hasDeleted && logger.isLoggable(Level.WARNING))
  					logger.warning("cannot delete file: " + fileName);
  			}
  		} catch (IOException e) {
  			if (logger.isLoggable(Level.WARNING))
  				logger.warning("there is something wrong when deleting " + fileName);
  			e.printStackTrace();
  		}
  	}
docs: Delete the specified file.
  
  @param fileName
  the name of the target file