我正在使用Fabric.io Twitter Kit。创建了一个自定义服务类，并使用Retrofit转换该类中的接口。底部的代码（CustomTwitterApiClient类）。
我得到NullPointerException，如果我抓住了，我得到JSONException。从日志中可以看出，我可以获得趋势响应，但我无法阅读它。如果我尝试readLine()并将其附加到StringBuilder，我会null。
我在此SO answer的指导下编写了代码。
我做错了什么？
提前致谢。
PS：那些额外的异常处理程序只是为了获得一个干净的日志。
D/LOG-DEBUG: Line 86 : [{"trends":[{"name":"#Worlds","url":"http:\/\/twitter.com\/search?q=%23Worlds","promoted_content":null,"query":"%23Worlds","tweet_volume":99974},{"name":"#LaNocheDeML","url":"http:\/\/twitter.com\/search?q=%23LaNocheDeML","promoted_content":null,"query":"%23LaNocheDeML","tweet_volume":56697},{"name":"#CLEMVSFSU","url":"http:\/\/twitter.com\/search?q=%23CLEMVSFSU","promoted_content":null,"query":"%23CLEMVSFSU","tweet_volume":10016},{"name":"#\u0634\u064A_\u062A\u062D\u0628_\u062A\u0634\u0645\u0647","url":"http:\/\/twitter.com\/search?q=%23%D8%B4%D9%8A_%D8%AA%D8%AD%D8%A8_%D8%AA%D8%B4%D9%85%D9%87","promoted_content":null,"query":"%23%D8%B4%D9%8A_%D8%AA%D8%AD%D8%A8_%D8%AA%D8%B4%D9%85%D9%87","tweet_volume":52441},{"name":"#DiosdadoEsPueblo","url":"http:\/\/twitter.com\/search?q=%23DiosdadoEsPueblo","promoted_content":null,"query":"%23DiosdadoEsPueblo","tweet_volume":44538},{"name":"Juanma","url":"http:\/\/twitter.com\/search?q=Juanma","promoted_content":null,"query":"Juanma","tweet_volume":13642},{"name":"Vince Vaughn","url":"http:\/\/twitter.com\/search?q=%22Vince+Vaughn%22","promoted_content":null,"query":"%22Vince+Vaughn%22","tweet_volume":10409},{"name":"Florida State","url":"http:\/\/twitter.com\/search?q=%22Florida+State%22","promoted_content":null,"query":"%22Florida+State%22","tweet_volume":10936},{"name":"Francois","url":"http:\/\/twitter.com\/search?q=Francois","promoted_content":null,"query":"Francois","tweet_volume":24324},{"name":"HOJE TEM TWD","url":"http:\/\/twitter.com\/search?q=%22HOJE+TEM+TWD%22","promoted_content":null,"query":"%22HOJE+TEM+TWD%22","tweet_volume":null},{"name":"Atividade Paranormal 4","url":"http:\/\/twitter.com\/search?q=%22Atividade+Paranormal+4%22","promoted_content":null,"query":"%22Atividade+Paranormal+4%22","tweet_volume":null},{"name":"BELIEBERS VOTANDO","url":"http:\/\/twitter.com\/search?q=%22BELIEBERS+VOTANDO%22","promoted_content":null,"query":"%22BELIEBERS+VOTANDO%22","tweet_volume":56259},{"name":"South Carolina","url":"http:\/\/twitter.com\/search?q=%22South+Carolina%22","promoted_content":null,"query":"%22South+Carolina%22","tweet_volume":16795},{"name":"Deshaun Watson","url":"http:\/\/twitter.com\/search?q=%22Deshaun+Watson%22","promoted_content":null,"query":"%22Deshaun+Watson%22","tweet_volume":12224},{"name":"Soulja Boy","url":"http:\/\/twitter.com\/search?q=%22Soulja+Boy%22","promoted_content":null,"query":"%22Soulja+Boy%22","tweet_volume":196642},{"name":"\uB864\uB4DC\uCEF5","url":"http:\/\/twitter.com\/search?q=%EB%A1%A4%EB%93%9C%EC%BB%B5","promoted_content":null,"query":"%EB%A1%A4%EB%93%9C%EC%BB%B5","tweet_volume":null},{"name":"Racing","url":"http:\/\/twitter.com\/search?q=Racing","promoted_content":null,"query":"Racing","tweet_volume":69655},{"name":"Jimbo","url":"http:\/\/twitter.com\/search?q=Jimbo","promoted_content":null,"query":"Jimbo","tweet_volume":null},{"name":"Silver Scrapes","url":"http:\/\/twitter.com\/search?q=%22Silver+Scrapes%22","promoted_content":null,"query":"%22Silver+Scrapes%22","tweet_volume":null},{"name":"#\u0627\u0646\u0627_\u0645\u0648\u0627\u0637\u0646_\u0645\u062B\u0644\u064A_\u0645\u062B\u0644\u0643\u0645","url":"http:\/\/twitter.com\/search?q=%23%D8%A7%D9%86%D8%A7_%D9%85%D9%88%D8%A7%D8%B7%D9%86_%D9%85%D8%AB%D9%84%D9%8A_%D9%85%D8%AB%D9%84%D9%83%D9%85","promoted_content":null,"query":"%23%D8%A7%D9%86%D8%A7_%D9%85%D9%88%D8%A7%D8%B7%D9%86_%D9%85%D8%AB%D9%84%D9%8A_%D9%85%D8%AB%D9%84%D9%83%D9%85","tweet_volume":23899},{"name":"#\u0627\u0637\u0631\u062F\u0648_\u0627\u0635\u062D\u0627\u0628_\u0627\u0644\u0642\u0647\u0648\u0647_\u0627\u0644\u0633\u0648\u062F\u0627\u0621","url":"http:\/\/twitter.com\/search?q=%23%D8%A7%D8%B7%D8%B1%D8%AF%D9%88_%D8%A7%D8%B5%D8%AD%D8%A7%D8%A8_%D8%A7%D9%84%D9%82%D9%87%D9%88%D9%87_%D8%A7%D9%84%D8%B3%D9%88%D8%AF%D8%A7%D8%A1","promoted_content":null,"query":"%23%D8%A7%D8%B7%D8%B1%D8%AF%D9%88_%D8%A7%D8%B5%D8%AD%D8%A7%D8%A8_%D8%A7%D9%84%D9%82%D9%87%D9%88%D9%87_%D8%A7%D9%84%D8%B3%D9%88%D8%AF%D8%A7%D8%A1","tweet_volume":null},{"name":"#\u0627\u0646\u0627_\u0645\u062F\u0627\u0648\u0
D/LOG-DEBUG: Line 111:
W/System.err: org.json.JSONException: End of input at character 0 of
W/System.err: at org.json.JSONTokener.syntaxError(JSONTokener.java:450)
W/System.err: at org.json.JSONTokener.nextValue(JSONTokener.java:97)
W/System.err: at org.json.JSONArray.<init>(JSONArray.java:92)
W/System.err: at org.json.JSONArray.<init>(JSONArray.java:108)
W/System.err: at .MainActivity$1$1.onResponse(MainActivity.java:113)
W/System.err: at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:68)
此代码阻止错误指向：
@Override
public void success(Result<TwitterSession> result) {
// The TwitterSession is also available through:
// Twitter.getInstance().core.getSessionManager().getActiveSession()
TwitterSession session = result.data;
// TODO: Remove toast and use the TwitterSession's userID
// with your app's user model
String msg = "@" + session.getUserName() + " logged in! (#" + session.getUserId() + ")";
Toast.makeText(getApplicationContext(), msg, Toast.LENGTH_LONG).show();
CustomTwitterApiClient customTwitterApiClient = new CustomTwitterApiClient(session);
Call<ResponseBody> cevap = customTwitterApiClient.getCustomService().show(1);
cevap.enqueue(new retrofit2.Callback<ResponseBody>() {
@Override
public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
BufferedReader reader = null;
StringBuilder stringBuilder2 = new StringBuilder();
try {
reader = new BufferedReader(new InputStreamReader(response.body().byteStream()));
} catch (Exception e) {
e.printStackTrace();
}
try {
Log.d("READER", "86 : reader.readLine() : "+reader.readLine());
} catch (IOException e) {
e.printStackTrace();
}
String line= "";
try{
while ((line = reader.readLine())!= null)
{
try {
stringBuilder2.append(line);
} catch (NullPointerException e) {
e.printStackTrace();
}
}
}
catch(IOException e){
e.printStackTrace();
}
try {
Log.d("READER", "111: stringBuilder2.toString(): " +stringBuilder2.toString());
} catch (Exception e) {
e.printStackTrace();
}
try {
JSONArray sonucJsonArray = new JSONArray(stringBuilder2.toString());
JSONObject sonucJsonObject = sonucJsonArray.getJSONObject(0);
JSONArray trendsJsonArray = sonucJsonObject.getJSONArray("trends");
JSONObject trendJson;
for(int i=0; i < trendsJsonArray.length() ; i++){
TrendTopic trend = new TrendTopic();
trendJson = trendsJsonArray.getJSONObject(i);
trend.set_id(i+1);
trend.set_trendName(trendJson.getString("name"));
trend.set_trendQuery(trendJson.getString("query"));
trend.set_trendURL(trendJson.getString("url"));
trendTopics.add(i,trend);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
@Override
public void onFailure(Call<ResponseBody> call, Throwable t) {
}
});
这是CustomTwitterApiClient类：
public class CustomTwitterApiClient extends TwitterApiClient {
public CustomTwitterApiClient(TwitterSession session) {
super(session);
}
public CustomService getCustomService() {
return getService(CustomService.class);
}
}
interface CustomService {
@GET("/1.1/trends/place.json")
Call<ResponseBody> show(@Query("id") int id);
}