访问JSON响应时分配引用

时间:2016-09-01 01:42:13

标签: java android json retrofit

我正在使用Retrofit和FlickRAPI查询FlickR数据库中的照片。

型号:

照片:

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;
      }
}

照片:

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;

    /**
     * @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响应:

{
  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"
       },

最终,我想得到照片的url_m,这是我的代码:

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()));

         if (response.body() == null){
             Log.v("RESPONSE_BODY", "RESPONSE_BODY_IS_NULL");
         }

         Log.v("RESPONSE_BODY", response.body().getTotal());
         List<Photo> photoResults = response.body().getPhoto();

         for (Photo photo : photoResults) {
             Log.v("PHOTO_URL:", photo.getTitle());
         }
     }

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

     }
});

现在,我收到一个NullPointer:

Process: com.troychuinard.flickr_test, PID: 2526
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.toString()' on a null object reference
at com.troychuinard.flickr_test.MainActivity$1$1.onResponse(MainActivity.java:65)
at retrofit2.ExecutorCallAdapterFactory$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)

0 个答案:

没有答案