java - Jsonreader解析错误

Question

我有以下代码:

reader = new JsonReader(new InputStreamReader(con.getInputStream()));

它返回以下 JSON:

{
  "results": [
    {
      "bioguide_id": "D000626",
      "in_office": true,
      "thomas_id": "02296",
      "govtrack_id": "412675",
      "crp_id": "N00038767",
      "fec_ids": [
        "H6OH08315"
      ],
      "first_name": "Warren",
      "nickname": null,
      "last_name": "Davidson",
      "middle_name": null,
      "name_suffix": null,
      "gender": "M",
      "birthday": "1970-03-01",
      "leadership_role": null,
      "term_start": "2016-06-09",
      "term_end": "2017-01-03",
      "state": "OH",
      "state_name": "Ohio",
      "party": "R",
      "title": "Rep",
      "chamber": "house",
      "phone": "202-225-6205",
      "fax": null,
      "website": null,
      "office": "1011 Longworth House Office Building",
      "contact_form": null,
      "votesmart_id": 166760,
      "district": 8,
      "oc_email": null,
      "ocd_id": "ocd-division/country:us/state:oh/cd:8"
    },
    {
      "bioguide_id": "L000585",
      "in_office": true,
      "thomas_id": "02295",
      "govtrack_id": "412674",
      "crp_id": "N00037031",
      "fec_ids": [
        "H6IL18088"
      ],
      "first_name": "Darin",
      "nickname": null,
      "last_name": "LaHood",
      "middle_name": null,
      "name_suffix": null,
      "gender": "M",
      "birthday": "1968-07-05",
      "leadership_role": null,
      "term_start": "2015-09-17",
      "term_end": "2017-01-03",
      "state": "IL",
      "state_name": "Illinois",
      "party": "R",
      "title": "Rep",
      "chamber": "house",
      "phone": "202-225-6201",
      "fax": null,
      "website": "https://lahood.house.gov/",
      "office": "2464 Rayburn House Office Building",
      "contact_form": "https://lahood.house.gov/contact/email",
      "votesmart_id": 128760,
      "district": 18,
      "oc_email": "Rep.Lahood@opencongress.org",
      "twitter_id": "RepLaHood",
      "youtube_id": null,
      "facebook_id": "1499570210366431",
      "ocd_id": "ocd-division/country:us/state:il/cd:18"
    }
  ],
  "count": 538,
  "page": {
    "count": 2,
    "per_page": 2,
    "page": 1
  }
}

我用以下方式解析读者:

try {

    reader.beginObject();
    while (reader.hasNext()) {
        String name = reader.nextName();
        if (name.equals("results")){
            reader.beginArray();
            while (reader.hasNext()) {
                reader.beginObject();
                while (reader.hasNext()) {
                    String id = reader.nextName();
                    if(id.equals("birthday"))
                        Log.d("id", id);
                    else
                        reader.skipValue();
                }
            }
        }

        else {
            reader.skipValue();
        }
    }

}
catch (IOException e){
    Log.w("Error",e.getMessage());
}

我收到以下错误:

E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.app.congress.congressapp, PID: 5095
java.lang.IllegalStateException: Expected a name but was STRING
   at android.util.JsonReader.nextName(JsonReader.java:390)
   at com.app.congress.congressapp.GetAllStates.onPostExecute(ByState.java:57)
   at com.app.congress.congressapp.GetAllStates.onPostExecute(ByState.java:30)
   at android.os.AsyncTask.finish(AsyncTask.java:636)
   at android.os.AsyncTask.access$500(AsyncTask.java:177)
   at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:653)
   at android.os.Handler.dispatchMessage(Handler.java:102)
   at android.os.Looper.loop(Looper.java:135)
   at android.app.ActivityThread.main(ActivityThread.java:5254)
   at java.lang.reflect.Method.invoke(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:372)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
E/AndroidRuntime: Error reporting crash
android.os.DeadObjectException
   at android.os.BinderProxy.transactNative(Native Method)
   at android.os.BinderProxy.transact(Binder.java:496)
   at android.app.ActivityManagerProxy.handleApplicationCrash(ActivityManagerNative.java:4164)
   at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:89)
   at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
   at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)

有没有办法以不同的方式解析 Jsonreader？我想要生日、end_term、bioguide_id 等字段的值。像这样手动解析它很困难，我必须进行许多其他 API 调用，这些调用可能会返回不同的 Json 结果，然后我又必须花时间解析它。我尝试使用 BufferedReader，但如果返回较大的 Json 文件，则会出现内存不足错误。

Answer 1

仔细看看你的代码:

                        String id = reader.nextName();
                        if(id.equals("birthday"))
                            Log.d("id", id);
                        else
                            reader.skipValue();

当“birthday”是属性名称时，您不会使用该值，因此在下一次循环中，您调用 nextName() 但解析器仍在该值上。

改用这个:

                        String id = reader.nextName();
                        if(id.equals("birthday")) {
                            Log.d("id", id);
                            reader.nextString(); // or reader.skipValue()
                        } else {
                            reader.skipValue();
                        }

正如评论所指出的，您需要为每个 beginObject() 提供一个匹配的 endObject() 和一个匹配的 endArray() > 对于每个 beginArray()。