无法从JSON输出中检索'totalResults'的值

Question

这是我得到的JSON输出：

{
  "status": "ok",
  "totalResults": 38,
  "articles": [
    {
      "source": {
        "id": null,
        "name": "Firstpost.com"
      },
      "author": null,
      "title": "Astronaut with blood clot on ISS gets successfully treated by doctor on Earth - Firstpost",
      "description": "The ISS had a limited supply of blood thinners that they had to make do with till the next re-supply mission.",
      "url": "https://www.firstpost.com/tech/science/astronaut-with-blood-clot-on-iss-gets-successfully-treated-by-doctor-on-earth-7866961.html",
      "urlToImage": "https://images.firstpost.com/wp-content/uploads/2018/08/ISS_NASA.jpg",
      "publishedAt": "2020-01-06T10:24:12Z",
      "content": "tech2 News StaffJan 06, 2020 15:54:12 IST\r\nHow on Earth does someone treat a life-threatening blood clot when you're in space? Dr Stephan Moll at the University of North Carolina School of Medicine a doctor and clotting expert can tell you how.\r\nIn an unprece… [+3928 chars]"
    }
  ]
}

这里是Profile.java：

public class Profile {

    @SerializedName("urlToImage")
    @Expose
    private String imageUrl;

    @SerializedName("title")
    @Expose
    private String title;

    @SerializedName("totalResults")
    @Expose
    private int totalResults;

    @SerializedName("url")
    @Expose
    private String url;

    public String getImageUrl() {
        return imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public int getTotalResults() {
        return totalResults;
    }

    public void setTotalResults(int totalResults) {
        this.totalResults = totalResults;
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }
}

这里是用于检索数据的AsyncTask：

class DownloadNews extends AsyncTask<String, Void, String> {
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }
        protected String doInBackground(String... args) {
            String xml = "";

            String urlParameters = "";
            xml = Function.excuteGet("https://newsapi.org/v2/top-headlines?country=in&apiKey="+API_KEY, urlParameters);
            return xml;
        }
        @Override
        protected void onPostExecute(final String xml) {

            if (xml != null) {
                if (xml.length() > 10) { // Just checking if not empty

                    Log.d("xml", xml);

                    for (final Profile profile : Utils.loadProfiles(getBaseContext(), xml)) {
                        PROGRESS_COUNT = profile.getTotalResults();
                        Log.d("PROGRESS_COUNT", String.valueOf(PROGRESS_COUNT));
                        storiesProgressView.setStoriesCount(PROGRESS_COUNT);
                        storiesProgressView.setStoryDuration(3000L);
                        storiesProgressView.startStories();
                    }

                } else {
                    Toast.makeText(getApplicationContext(), "No news found", Toast.LENGTH_SHORT).show();
                }
            } else {
                Log.d("xml", "Null");
            }
        }

    }

这里是Utils.java：

public class Utils {

    private static final String TAG = "Utils";

    public static List<Profile> loadProfiles(Context context, String xml) {

        try {
            JSONObject jsonResponse = new JSONObject(xml);
            JSONArray jsonArray = jsonResponse.optJSONArray("articles");
            GsonBuilder builder = new GsonBuilder();
            Gson gson = builder.create();
            List<Profile> profileList = new ArrayList<>();

            for (int i = 0; i < jsonArray.length(); i++) {
                Profile profile = gson.fromJson(jsonArray.getString(i), Profile.class);
                profileList.add(profile);
            }
            return profileList;
        } catch (JSONException e) {
            Toast.makeText(context.getApplicationContext(), e.getMessage(), Toast.LENGTH_SHORT).show();
            return null;
        }

    }
}

您可以在上面的JSON输出中看到，totalResults是38，但是在AsyncTask类的日志中，它显示的是D/PROGRESS_COUNT: 0

我在这里做错了什么？

Answer 1

Option-1：更新您的代码以将totalResults包含在每个Profile中。检查以下：

JSONObject jsonResponse = new JSONObject(xml);
JSONArray jsonArray = jsonResponse.optJSONArray("articles");

// parse the total result
int totalResults = jsonResponse.optInt("totalResults");

GsonBuilder builder = new GsonBuilder();
Gson gson = builder.create();
List<Profile> profileList = new ArrayList<>();

for (int i = 0; i < jsonArray.length(); i++) {
    Profile profile = gson.fromJson(jsonArray.getString(i), Profile.class);

    // set totalResults to each profile
    profile.setTotalResults(totalResults);

    profileList.add(profile);
}

return profileList;

选项-2：如下更新模型以与json响应相匹配：

Article.java：

public class Article {

    @SerializedName("status")
    @Expose
    private String status;

    @SerializedName("totalResults")
    @Expose
    private int totalResults;

    @SerializedName("articles")
    @Expose
    private List<Profile> articles;

    // getter-setter
}

Profile.java：

public class Profile {

    @SerializedName("urlToImage")
    @Expose
    private String imageUrl;

    @SerializedName("title")
    @Expose
    private String title;

    @SerializedName("url")
    @Expose
    private String url;

    // getter-setter
}

然后像下面一样解析您的json：

Article article = gson.fromJson(xml, Article.class);