public static AccessToken getAccessToken(String appid, String appsecret) {
		AccessToken accessToken = null;

		String requestUrl = access_token_url.replace("APPID", appid).replace(
				"APPSECRET", appsecret);
		JSONObject jsonObject = httpRequest(requestUrl, "GET", null);
		// ɹ
		if (null != jsonObject) {
			try {
				accessToken = new AccessToken();
				accessToken.setToken(jsonObject.getString("access_token"));
				accessToken.setExpiresIn(jsonObject.getInt("expires_in"));
			} catch (Exception e) {
				accessToken = null;
				// ȡtokenʧ
				log.error("ȡtokenʧ errcode:{} errmsg:{}",
						jsonObject.getInt("errcode"),
						jsonObject.getString("errmsg"));
			}
		}
		return accessToken;
	}