Facebook Graph Api呼叫返回状态200 Android中没有内容

Question

我正在调用facebook的图表api，它返回的状态为200，但内容为空。当我在浏览器中进行完全相同的调用时，它返回数据。有任何想法吗？以下是我尝试拨打的电话的代码段：

        String appAccessToken = ((TestApplication)observer.getContext().getApplicationContext()).getAppAccessToken();
        String url = "https://graph.facebook.com/search?q=school&type=place&access_token=" + URLEncoder.encode(appAccessToken, "UTF8") ;

        DefaultHttpClient client = new DefaultHttpClient();

        HttpGet get = new HttpGet(url);
        HttpResponse response = client.execute(get);