Question

当我正在编译应用程序时，它不会更新Textviews，即使它没有在Android监视器上显示任何错误。有人可以解释我如何将JSON映射到java对象和数组吗？

主要Activity.java

public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
private MovieDetails mmoviedetails;
private TextView Title;
private TextView id;
private TextView releasedate;
private TextView originaltitle;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    Title=(TextView)findViewById(R.id.titleid);
    id=(TextView)findViewById(R.id.id);
    releasedate=(TextView)findViewById(R.id.releasedateid);
    originaltitle=(TextView)findViewById(R.id.originaltitleid);



    String forecastUrl = "https://api.themoviedb.org/3/movie/550?api_key=6d349f745d2d8b31d1bfd1cccfbd7e0";
    if (isNetworkAvailable()) {
        OkHttpClient client = new OkHttpClient();
        Request request = new Request.Builder()
                .url(forecastUrl)
                .build();

        Call call = client.newCall(request);
        call.enqueue(new Callback() {
            @Override
            public void onFailure(Call call, IOException e) {

            }

            @Override
            public void onResponse(Call call, Response response) throws IOException {
                try {
                    String jsonData = response.body().string();
                    Log.v(TAG, jsonData);
                    if (response.isSuccessful()) {
                        mmoviedetails = getCurrentDetails(jsonData);
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                updateDisplay();
                            }
                        });

                    } else {
                        alertUserAboutError();
                    }
                }
                catch (IOException e) {
                    Log.e(TAG, "Exception caught: ", e);
                }
                catch (JSONException e) {
                    Log.e(TAG, "Exception caught: ", e);
                }
            }
        });
    }
    else {
        Toast.makeText(this, getString(R.string.network_unavailable_message),
                Toast.LENGTH_LONG).show();
    }

    Log.d(TAG, "Main UI code is running!");
}

private void updateDisplay() {

    originaltitle.setText(mmoviedetails.getOriginal_title()+"");
    id.setText(mmoviedetails.getId()+"");
    Title.setText(mmoviedetails.getTitle()+"");
    releasedate.setText(mmoviedetails.getRelease_date()+"");
}

private MovieDetails getCurrentDetails(String jsonData) throws JSONException {
    JSONObject forecast = new JSONObject(jsonData);
    JSONObject currently = forecast.getJSONObject("JSON");

    MovieDetails moviedetails = new MovieDetails();
    moviedetails.setId(currently.getInt("Id"));
    moviedetails.setOriginal_title(currently.getString("Original_title"));
    moviedetails.setTitle(currently.getString("Title"));
    moviedetails.setRelease_date(currently.getString("Release_date"));
    return moviedetails;
}


private boolean isNetworkAvailable() {
    ConnectivityManager manager = (ConnectivityManager)
            getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo networkInfo = manager.getActiveNetworkInfo();
    boolean isAvailable = false;
    if (networkInfo != null && networkInfo.isConnected()) {
        isAvailable = true;
    }

    return isAvailable;
}

private void alertUserAboutError() {

}

MovieDetails.java

public class MovieDetails {
private String Title;
private String Release_date;
private int Id;
private String original_title;

public String getTitle() {
    return Title;
}

public void setTitle(String title) {
    Title = title;
}

public String getRelease_date() {
    return Release_date;
}

public void setRelease_date(String release_date) {
    Release_date = release_date;
}

public int getId() {
    return Id;
}

public void setId(int id) {
    Id = id;
}

public String getOriginal_title() {
    return original_title;
}

public void setOriginal_title(String original_title) {
    this.original_title = original_title;
}}

提前致谢。

Answer 1

你所提到的api没有给出无效的api错误（我假设你故意发错了（y））
api我正在使用我自己的api密钥就是这样的

{
  "adult": false,
  "backdrop_path": "/wSJPjqp2AZWQ6REaqkMuXsCIs64.jpg",
  "belongs_to_collection": null,
  "budget": 63000000,
  "genres": [
    {
      "id": 18,
      "name": "Drama"
    }
  ],
  "homepage": "http://www.foxmovies.com/movies/fight-club",
  "id": 550,
  "imdb_id": "tt0137523",
  "original_language": "en",
  "original_title": "Fight Club",
  "overview": "A ticking-time-bomb insomniac and a slippery soap salesman     channel      primal male aggression into a shocking new form of therapy. Their      concept catches on, with underground \"fight clubs\" forming in every town, until     an eccentric gets in the way and ignites an out-of-control spiral toward     oblivion.",
  "popularity": 5.419718,
  "poster_path": "/adw6Lq9FiC9zjYEpOqfq03ituwp.jpg",
  "production_companies": [
    {
      "name": "Regency Enterprises",
      "id": 508
    },
    {
      "name": "Fox 2000 Pictures",
      "id": 711
    },
    {
      "name": "Taurus Film",
      "id": 20555
    },
    {
      "name": "Linson Films",
      "id": 54050
    },
    {
      "name": "Atman Entertainment",
      "id": 54051
    },
    {
      "name": "Knickerbocker Films",
      "id": 54052
    }
  ],
  "production_countries": [
    {
      "iso_3166_1": "DE",
      "name": "Germany"
    },
    {
      "iso_3166_1": "US",
      "name": "United States of America"
    }
  ],
  "release_date": "1999-10-14",
  "revenue": 100853753,
  "runtime": 139,
  "spoken_languages": [
    {
      "iso_639_1": "en",
      "name": "English"
    }
  ],
  "status": "Released",
  "tagline": "How much can you know about yourself if you've never been in a                   fight?",
  "title": "Fight Club",
  "video": false,
  "vote_average": 8.1,
  "vote_count": 5876
}

现在这是一个带有大量jsonarrays的大JSON值你所制作的POJO，即MovieDetails.java没有上述字段
向你解释一下pojo是如何制作的几点

每次内容都包含在{}中时你必须创建一个单独的pojo，所以有默认的根{}之后我们必须为每个JSONArray制作单独的pojos，这里的json数组被命名为“genres”， “production_companies”，“生产国家”，“口语语言”这样共有5个pojos，我们将其命名为MainPojo.java，Genres.java，Prod1.java，Prod2.java，Spoken.java
使pojos成为一项简单的任务，您可以在线使用POJO生成器，例如。 http://www.jsonschema2pojo.org/
在你主要的pojo中你必须为ex定义不同POJO类型的arraylists。 ArrayList genre = new ArrayList（）;和休息一样

现在已经到了解你如何解析这些数据的问题为此你可以使用杰克逊或Gson的图书馆或者使用JSONObject和JSONArray类

{}内的元素是JSONObjects，包裹[]的元素是json数组
这里是genre，production_companies，production_countries，spoken_languages是json数组

基本上你的解析就像这样

MainPojo main = new MainPojo();
 JSONObject jo = new JSONObject(url);
 main.adult = jo.getString("adult"); //remember the string that is passed in     as argument should be same as you see in the json  and you should be using getter ans setters for assigning values
main.backdrop = jo.getString("backdrop_path"); and so on 
.  
.  
.  
.  
//now we know genres is a jsonarray so  
Genres g;

 JSONArray genres = jo.getJSONArray("genres");
  for(int i =0;i<genres.length();i++)
   {
     g  = new Genres();
     JSONObject genObject = genres.getJSONObject(i);
     g.id = genObject.getString("id");
     genres.add(g);
   }

每隔一个jsonarray都会遵循相同的程序我建议你从我提到的链接生成api的POJO，以便更好地澄清!!

希望它有所帮助！

无法通过OKhttp库解析数据

1 个答案: