@Override
	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		
		Map<String, String[]> param = request.getParameterMap();

		if (param != null) {
			Path logfile = FileSystems.getDefault().getPath("G:\\workspace\\TelephoneBook-v2\\file.log");
			byte buf[] = param.toString().getBytes();
			try {
				Files.write(logfile, buf, StandardOpenOption.APPEND);
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
		chain.doFilter(request, response);
	}