private Response get(String url, PostParameter[] params,
				boolean authenticate) throws WeiboException {
			if (url.indexOf("?") == -1) {
				url += "?source=" + sinaAppKey;
			} else if (url.indexOf("source") == -1) {
				url += "&source=" + sinaAppKey;
			}
			if (null != params && params.length > 0) {
				url += "&" + HttpClient.encodeParameters(params);
			}
			return http.get(url, authenticate);
		}