JsonReader抛出IllegalStateException

Question

我发现使用http://ip-api.com/json是获取必要用户位置详细信息的简便方法。结果，例如来自网站的结果是：

{"as":"AS37061 ONECOM","city":"Nairobi","country":"Kenya","countryCode":"KE","isp":"One Communications Ltd","lat":-1.2833,"lon":36.8167,"org":"ONECOM","query":"41.203.219.198","region":"110","regionName":"Nairobi Province","status":"success","timezone":"Africa/Nairobi","zip":""}

我用以下代码解析了上面的Json结果：

String countryCode = null;
    String name = null;

    if (reader != null) {
        try {
            reader.setLenient(true);

            reader.beginObject();

            while (reader.hasNext()) {
                switch (reader.nextName()) {
                    case "countryCode":
                        countryCode = reader.nextString().toLowerCase();
                        break;
                    case "country":
                        name = reader.nextString();
                        break;
                    default:
                        reader.skipValue();
                        break;
                }
            }

            reader.endObject();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

现在我收到了这个错误：

Fatal Exception: java.lang.IllegalStateException: Expected BEGIN_OBJECT but was END_DOCUMENT at line 1 column 2016
   at com.google.gson.stream.JsonReader.beginObject(JsonReader.java:374)
   at com.radioafrica.music.fragment.TopTracks.getCountryCode(TopTracks.java:397)
   at com.radioafrica.music.fragment.TopTracks.access$1100(TopTracks.java:57)
   at com.radioafrica.music.fragment.TopTracks$9.run(TopTracks.java:377)
   at java.lang.Thread.run(Thread.java:818)

据我所知，代码很好，但它并不总是有效。什么似乎是问题？