public String sparkLineUrl(String host, String service, String dataSource, int width, int height, boolean withMetaData) throws Exception
	{
		String url = "/cgi-bin/sparkline.cgi?width=" + width + "&height=" + height + "&host=" + URLEncoder.encode(host, defaultCharset);
		if (service != null)
			url += "&service=" + URLEncoder.encode(service, defaultCharset);
		if (dataSource != null)
			url += "&dataSource=" + URLEncoder.encode(dataSource, defaultCharset);
		url += "&metadata=" + (withMetaData ? "true" : "false");

		return url;
	}