code: public final static Cookie getCookie(HttpServletRequest httpServletRequest, String name) {
  		final Map<String, Cookie> cookieMap = readCookieMap(httpServletRequest);
  		return cookieMap == null ? null : cookieMap.get(name);
  	}
docs: 获得指定的Cookie
  
  @param httpServletRequest {@link HttpServletRequest}
  @param name cookie名
  @return Cookie对象