code: public static String href(String param, String value) {
  		HttpServletRequest req = ContextUtils.getRequest();
  		String pagePath = (String) req.getAttribute(SiteController.PAGE_PATH);
  		if (pagePath == null)
  			return "javascript:void(0)";
  		StaticUrlProvider urlProvider = (StaticUrlProvider) req
  				.getAttribute(StaticUrlProvider.REQ_ATTR_KEY);
  		if (urlProvider == null)
  			return "javascript:void(0)";
  		String url = urlProvider.getUrl(param, value);
  		if (url == null)
  			return pagePath;
  		if (url.startsWith("/"))
  			return pagePath + url.substring(1);
  		return pagePath + url;
  	}
docs: 生成静态链接