Retrofit Returning Null Response Body

Question

Ich versuche, einen Anruf an die FlickR API und habe Schwierigkeiten, da die Antwort.body() Null zurückgibt.

Ich bin mir nicht sicher, ob es sich um mein JSON/POJO-Mapping handelt, aber ich kann nicht herausfinden, wie ich auf die Antwort von Retrofit zugreifen kann, wenn ich FlickR anrufe. Ich weiß, dass mein Anruf erfolgreich abgeschlossen wird, da ich den JSON über den Logging-Interceptor tatsächlich anzeigen kann.

Modell:

public class Model { 

Photos photos; 
int code; 
String stat; 
String message; // when you text = null 

public class Photos { 

    @SerializedName("page") 
    @Expose 
    private int page; 
    @SerializedName("pages") 
    @Expose 
    private int pages; 
    @SerializedName("perpage") 
    @Expose 
    private int perpage; 
    @SerializedName("total") 
    @Expose 
    private String total; 
    @SerializedName("photo") 
    @Expose 
    private List<Photo> photo = new ArrayList<Photo>(); 

    /** 
    * @return The page 
    */ 
    public int getPage() { 
     return page; 
    } 

    /** 
    * @param page The page 
    */ 
    public void setPage(int page) { 
     this.page = page; 
    } 

    /** 
    * @return The pages 
    */ 
    public int getPages() { 
     return pages; 
    } 

    /** 
    * @param pages The pages 
    */ 
    public void setPages(int pages) { 
     this.pages = pages; 
    } 

    /** 
    * @return The perpage 
    */ 
    public int getPerpage() { 
     return perpage; 
    } 

    /** 
    * @param perpage The perpage 
    */ 
    public void setPerpage(int perpage) { 
     this.perpage = perpage; 
    } 

    /** 
    * @return The total 
    */ 
    public String getTotal() { 
     return total; 
    } 

    /** 
    * @param total The total 
    */ 
    public void setTotal(String total) { 
     this.total = total; 
    } 

    /** 
    * @return The photo 
    */ 
    public List<Photo> getPhoto() { 
     return photo; 
    } 

    /** 
    * @param photo The photo 
    */ 
    public void setPhoto(List<Photo> photo) { 
     this.photo = photo; 
    } 

} 

public class Photo { 

    @SerializedName("id") 
    @Expose 
    private String id; 
    @SerializedName("owner") 
    @Expose 
    private String owner; 
    @SerializedName("secret") 
    @Expose 
    private String secret; 
    @SerializedName("server") 
    @Expose 
    private String server; 
    @SerializedName("farm") 
    @Expose 
    private int farm; 
    @SerializedName("title") 
    @Expose 
    private String title; 
    @SerializedName("ispublic") 
    @Expose 
    private int ispublic; 
    @SerializedName("isfriend") 
    @Expose 
    private int isfriend; 
    @SerializedName("isfamily") 
    @Expose 
    private int isfamily; 
    @SerializedName("url_m") 
    @Expose 
    private String urlM; 
    @SerializedName("height_m") 
    @Expose 
    private String heightM; 
    @SerializedName("width_m") 
    @Expose 
    private String widthM; 

    public Photo(){ 

    } 

    /** 
    * @return The id 
    */ 
    public String getId() { 
     return id; 
    } 

    /** 
    * @param id The id 
    */ 
    public void setId(String id) { 
     this.id = id; 
    } 

    /** 
    * @return The owner 
    */ 
    public String getOwner() { 
     return owner; 
    } 

    /** 
    * @param owner The owner 
    */ 
    public void setOwner(String owner) { 
     this.owner = owner; 
    } 

    /** 
    * @return The secret 
    */ 
    public String getSecret() { 
     return secret; 
    } 

    /** 
    * @param secret The secret 
    */ 
    public void setSecret(String secret) { 
     this.secret = secret; 
    } 

    /** 
    * @return The server 
    */ 
    public String getServer() { 
     return server; 
    } 

    /** 
    * @param server The server 
    */ 
    public void setServer(String server) { 
     this.server = server; 
    } 

    /** 
    * @return The farm 
    */ 
    public int getFarm() { 
     return farm; 
    } 

    /** 
    * @param farm The farm 
    */ 
    public void setFarm(int farm) { 
     this.farm = farm; 
    } 

    /** 
    * @return The title 
    */ 
    public String getTitle() { 
     return title; 
    } 

    /** 
    * @param title The title 
    */ 
    public void setTitle(String title) { 
     this.title = title; 
    } 

    /** 
    * @return The ispublic 
    */ 
    public int getIspublic() { 
     return ispublic; 
    } 

    /** 
    * @param ispublic The ispublic 
    */ 
    public void setIspublic(int ispublic) { 
     this.ispublic = ispublic; 
    } 

    /** 
    * @return The isfriend 
    */ 
    public int getIsfriend() { 
     return isfriend; 
    } 

    /** 
    * @param isfriend The isfriend 
    */ 
    public void setIsfriend(int isfriend) { 
     this.isfriend = isfriend; 
    } 

    /** 
    * @return The isfamily 
    */ 
    public int getIsfamily() { 
     return isfamily; 
    } 

    /** 
    * @param isfamily The isfamily 
    */ 
    public void setIsfamily(int isfamily) { 
     this.isfamily = isfamily; 
    } 

    /** 
    * @return The urlM 
    */ 
    public String getUrlM() { 
     return urlM; 
    } 

    /** 
    * @param urlM The url_m 
    */ 
    public void setUrlM(String urlM) { 
     this.urlM = urlM; 
    } 

    /** 
    * @return The heightM 
    */ 
    public String getHeightM() { 
     return heightM; 
    } 

    /** 
    * @param heightM The height_m 
    */ 
    public void setHeightM(String heightM) { 
     this.heightM = heightM; 
    } 

    /** 
    * @return The widthM 
    */ 
    public String getWidthM() { 
     return widthM; 
    } 

    /** 
    * @param widthM The width_m 
    */ 
    public void setWidthM(String widthM) { 
     this.widthM = widthM; 
    } 

    } 

} 

JSON Antwort:

{ 
    photos: { 
    page: 1, 
    pages: 3683, 
    perpage: 100, 
    total: "368270", 
    photo: [ 
     { 
     id: "29264707352", 
     owner: "84316756@N02", 
     secret: "9ed355a86e", 
     server: "8603", 
     farm: 9, 
     title: "Tercer Patio de los Claustros de la Compañía/ Arequipa", 
     ispublic: 1, 
     isfriend: 0, 
     isfamily: 0, 
     url_m:   "https://farm9.staticflickr.com/8603/29264707352_9ed355a86e.jpg", 
     height_m: "500", 
     width_m: "333" 
      }, 
     { 
     id: "29339070436", 
     owner: "146617764@N02", 
     secret: "b52f1e9914", 
     server: "8509", 
     farm: 9, 
     title: "2016-04-17 09.24.07", 
     ispublic: 1, 
     isfriend: 0, 
     isfamily: 0, 
     url_m: "https://farm9.staticflickr.com/8509/29339070436_b52f1e9914.jpg", 
     height_m: "281", 
     width_m: "500" 
     }, 

Logcat

09-03 15:11:33.037 1846-1846/com.troychuinard.flickr_test E/AndroidRuntime: FATAL EXCEPTION: main 
                      Process: com.troychuinard.flickr_test, PID: 1846 
                      java.lang.NullPointerException: println needs a message 
                       at android.util.Log.println_native(Native Method) 
                       at android.util.Log.v(Log.java:118) 
                       at com.troychuinard.flickr_test.MainActivity$1$1.onResponse(MainActivity.java:72) 
                       at retrofit2.ExecutorCallAdapterFactory$ExecutorCallbackCall$1$1.run(ExecutorCallAdapterFactory.java:68) 
                       at android.os.Handler.handleCallback(Handler.java:739) 
                       at android.os.Handler.dispatchMessage(Handler.java:95) 
                       at android.os.Looper.loop(Looper.java:135) 
                       at android.app.ActivityThread.main(ActivityThread.java:5254) 
                       at java.lang.reflect.Method.invoke(Native Method) 
                       at java.lang.reflect.Method.invoke(Method.java:372) 
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903) 
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698) 
09-03 15:14:21.858 1846-1846/com.troychuinard.flickr_test I/Process: Sending signal. PID: 1846 SIG: 9 

Linie 72

  Log.v("RESPONSE_BODY", response.body().getTotal()); 

Aktivität

public class MainActivity extends AppCompatActivity { 

private EditText mSearchTerm; 
private Button mRequestButton; 
private Button mSearchButton; 
private String mQuery; 

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

    mSearchTerm = (EditText) findViewById(R.id.ediText_search_term); 
    mRequestButton = (Button) findViewById(R.id.request_button); 
    mSearchButton = (Button) findViewById(R.id.search_button_flickr); 
    mRequestButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      mQuery = mSearchTerm.getText().toString(); 
      HttpLoggingInterceptor interceptor = new HttpLoggingInterceptor(); 
      interceptor.setLevel(HttpLoggingInterceptor.Level.BODY); 
      OkHttpClient client = new OkHttpClient.Builder().addInterceptor(interceptor).build(); 
      Retrofit retrofit = new Retrofit.Builder() 
        .baseUrl("https://api.flickr.com/services/rest/") 
        .client(client) 
        .addConverterFactory(GsonConverterFactory.create()) 
        .build(); 


      ApiInterface apiInterface = retrofit.create(ApiInterface.class); 
      Call<Photos> call = apiInterface.getImages(mQuery); 
      call.enqueue(new Callback<Photos>() { 
       @Override 
       public void onResponse(Call<Photos> call, Response<Photos> response) { 
        Log.v("RESPONSE_CALLED", "ON_RESPONSE_CALLED"); 
        String didItWork = String.valueOf(response.isSuccessful()); 
        Log.v("SUCCESS?", didItWork); 
        Log.v("RESPONSE_CODE", String.valueOf(response.code())); 
        Photos photos = response.body(); 
        Log.v("RESPONSE_BODY", "response:" + photos); 
        String total = response.body().getTotal(); 
        Log.v("Total", total); 
        List<Photos.Photo> photoResults = response.body().getPhoto(); 
        for (Photos.Photo photo : photoResults) { 
         Log.v("PHOTO_URL:", photo.getTitle() 
         ); 
        } 


       } 

       @Override 
       public void onFailure(Call<Photos> call, Throwable t) { 

       } 
      }); 
     } 
    }); 

    mSearchButton.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View view) { 
      Intent toSearch = new Intent(MainActivity.this, FlickRActivity.class); 
      startActivity(toSearch); 
     } 
    }); 


} 

//Synchronous vs. Asynchronous 
public interface ApiInterface { 

    @GET("?method=flickr.photos.search&api_key=1c448390199c03a6f2d436c40defd90e&format=json&nojsoncallback=1&extras=url_m") 
    Call<Photos> getImages(@Query("text") String query); 

} 

}

Answer 1

Aufgrund meiner vorherigen Antwort here Ihr Modell ist nicht korrekt Ihre stat: "ok" am Ende der Reaktion ist dein Fehler.

Während Sie ein Photos Objekt erstellen müssen Sie ein übergeordnetes Modell sowohl Attribut zu halten (photos & stat)

So würde Ihr Modell sein:

public class Model { 

    Photos photos; 
    int code; 
    String stat; 
    String message; // when you text = null 


    public class Photos{ 
     int page; 
     int pages; 
     int perpage; 
     int total; 
     List<Photo> photo; 



     public class Photo{ 
      String id; 
      String owner; 
      String secret; 
      //rest of things 

     } 
    } 
} 

Vergessen Sie auch nicht Ihre Call<Photos> zu ändern zu Call<Model>.