Deserializing inner class when using GSON and Retrofit

Question

My api response is like:

 "stories": [
    {
      "id": 3509,
      "title": "Greece financial crises ",
      "isBreaking": "0",
      "updated": "1435719565",
      "readers": "0",

      "feed": [
        {
          "feed_id": "2",
          "title": "cnn",
          "logo_url": "http:\\/\\/cnn.com\\/images\\/logo.gif",
          "site_url": "http:\\/\\/cnn.com\\/news.php\\/"
        }
      ]
    },

For that, i have created two classes. The first one is StoryAbstact class which has field feed of type Feeds class

 public class StoryAbstract {

        private long id;
        private String title;
        private int isBreaking;
        private Long updated;
        private long readers;
        private String date;
        private String image;
        private List<Feeds> feed;
        ..
        // getters and getters
        public List<Feeds> getFeed() {
            return feed;
        }

        public void setFeed(List<Feeds> feed) {
            this.feed = feed;
        }

        ....
        ....

The second class is Feeds like:

public class Feeds {
    private int feed_id;
    private String title;
    private String logo_url;
    private String site_url;
    ..
        // getters & setters
    public int getFeed_id() {
        return feed_id;
    }

    public void setFeed_id(int feed_id) {
        this.feed_id = feed_id;
    }

    public String getTitle() {
        return title;
    }

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

    public String getLogo_url() {
        return logo_url;
    }

    public void setLogo_url(String logo_url) {
        this.logo_url = logo_url;
    }

    public String getSite_url() {
        return site_url;
    }

    public void setSite_url(String site_url) {
        this.site_url = site_url;
    }

    //setters
}

I want to show information from both classes ( StoryAbstract and Feeds ) in my recyclerView adapter and for that, i am able to get the data deserialized from first class but only null from the second class.

i think this is due to that, the second class is not deserialized and i am not able to solve it. i am using Retrofit 1.9.0.

Any help please...

Edit

I have followed the answers below but none of them have solved my problem. i believe i have some thing wrong when i call the Feed class in my adapter. my adapter code is like:

 private static class ViewHolderItem extends RecyclerView.ViewHolder implements View.OnClickListener {

        private final TextView txtTitle;
        private final ImageView imageIcon;
        private final TextView feedName;
        private Context context;
        private StoryAbstract story;
        private TextView timeStamp;
        private Feeds feed;

        public ViewHolderItem(View itemView, Context context) {
            super(itemView);

            this.context = context;
            txtTitle = (TextView) itemView.findViewById(R.id.list_item_title);
            imageIcon = (ImageView) itemView.findViewById(R.id.list_item_image);
            feedName = (TextView) itemView.findViewById(R.id.feedName);
                   itemView.setOnClickListener(this);
        }

        public void bindStory(StoryAbstract story) {
            this.story = story;
            txtTitle.setText(story.getTitle());
            feedName.setText(feed.getTitle());
            String imageUrl = story.getImageUrl();
            if (!TextUtils.isEmpty(imageUrl)) {
                Ion.with(imageIcon)
                        .placeholder(R.drawable.loading)
                        .error(R.drawable.loading)
                        .load(imageUrl);
                imageIcon.setVisibility(View.VISIBLE);
            } else {
                imageIcon.setVisibility(View.GONE);
            }
        }

feedName.setText(feed.getTitle()); returns null

Answer 1

Try this:

public class JsonModel implements Serializable {

    private static final long serialVersionUID = -6186015239095323524L;

}

public class Feed extends JsonModel {
  private static final long serialVersionUID = -8152796378433288199L;

  @SerializedName("feed_id")
  private int feedId;

  @SerializedName("title")
  private String title;

  @SerializedName("logo_url")
  private String logoUrl;

  @SerializedName("site_url")
  private String siteUrl;

  public int getFeedId() {
    return feedId;
  }

  public void setFeedId(int feedId) {
      this.feedId = feedId;
  }

  public String getTitle() {
     return title;
  }

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

  public String getLogoUrl() {
    return logoUrl;
  }

  public void setLogoUrl(String logoUrl) {
    this.logoUrl = logoUrl;
  }

  public String getSiteUrl() {
    return siteUrl;
  }

  public void setSiteUrl(String siteUrl) {
    this.siteUrl = siteUrl;
  }

}

public class StoryAbstract extends JsonModel{

private static final long serialVersionUID = 1269037550260848268L;

@SerializedName("id")
private long id;

@SerializedName("title")
private String title;

@SerializedName("isBreaking")
private int isBreaking;

@SerializedName("updated")
private long updated;

@SerializedName("readers")
private long readers;

@SerializedName("feed")
private Feed feed;

public long getId() {
    return id;
}

public void setId(long id) {
    this.id = id;
}

public String getTitle() {
    return title;
}

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

public int getIsBreaking() {
    return isBreaking;
}

public void setIsBreaking(int isBreaking) {
    this.isBreaking = isBreaking;
}

public long getUpdated() {
    return updated;
}

public void setUpdated(long updated) {
    this.updated = updated;
}

public long getReaders() {
    return readers;
}

public void setReaders(long readers) {
    this.readers = readers;
}

public Feed getFeed() {
    return feed;
}

public void setFeed(Feed feed) {
    this.feed = feed;
}

}

And finally:

public class StoriesResponse extends JsonModel{
private static final long serialVersionUID = -2329376390030680204L;

@SerializedName("stories")
private List<StoryAbstract> storyAbstracts;

public List<StoryAbstract> getStoryAbstracts() {
    return storyAbstracts;
}

public void setStoryAbstracts(List<StoryAbstract> storyAbstracts) {
    this.storyAbstracts = storyAbstracts;
}

}

Just add StoriesResponse in your Retrofit Callback.

Answer 2

Im not be able to reproduce your error, but I have created an example using your json response, and this approach is working fine:

JSON

private static String JSON = "{\"stories\":[{\"id\":3509,\"title\":\"Greecefinancialcrises\",\"isBreaking\":\"0\",\"updated\":\"1435719565\",\"readers\":\"0\",\"feed\":[{\"feed_id\":\"2\",\"title\":\"cnn\",\"logo_url\":\"http:\\\\/\\\\/cnn.com\\\\/images\\\\/logo.gif\",\"site_url\":\"http:\\\\/\\\\/cnn.com\\\\/news.php\\\\/\"}]}]}";

StoriesResponse class

public static class StoriesResponse {
        private List<Story> stories;

        public List<Story> getStories() {
            return stories;
        }

        @Override
        public String toString() {
            return "StoriesResponse{" +
                    "stories=" + stories +
                    '}';
        }
    }

Story class

public static class Story {
        private long id;
        private String title;
        private int isBreaking;
        private long updated;
        private int readers;
        private List<Feed> feed;

        public long getId() {
            return id;
        }

        public String getTitle() {
            return title;
        }

        public int getIsBreaking() {
            return isBreaking;
        }

        public long getUpdated() {
            return updated;
        }

        public int getReaders() {
            return readers;
        }

        public List<Feed> getFeed() {
            return feed;
        }

        @Override
        public String toString() {
            return "Story{" +
                    "id=" + id +
                    ", title='" + title + '\'' +
                    ", isBreaking=" + isBreaking +
                    ", updated=" + updated +
                    ", readers=" + readers +
                    ", feed=" + feed +
                    '}';
        }
    }

Feed class

public static class Feed {
        private long feed_id;
        private String title;
        private String logo_url;
        private String site_url;

        public long getFeed_id() {
            return feed_id;
        }

        public String getTitle() {
            return title;
        }

        public String getLogo_url() {
            return logo_url;
        }

        public String getSite_url() {
            return site_url;
        }

        @Override
        public String toString() {
            return "Feed{" +
                    "feed_id=" + feed_id +
                    ", title='" + title + '\'' +
                    ", logo_url='" + logo_url + '\'' +
                    ", site_url='" + site_url + '\'' +
                    '}';
        }
    }

Main method to test it:

Gson gson = new Gson();
StoriesResponse response = gson.fromJson(JSON,StoriesResponse.class);

LOG(response);

The response given by toString() implementation is:

StoriesResponse{stories=[Story{id=3509, title='Greecefinancialcrises', isBreaking=0, updated=1435719565, readers=0, feed=[Feed{feed_id=2, title='cnn', logo_url='http:\/\/cnn.com\/images\/logo.gif', site_url='http:\/\/cnn.com\/news.php\/'}]}]}

They are all static classes because I've opened a new project to test this.

This is not a solution, but I have reproduced the steps that Gson do within retrofit lib.

I always use a kind of a wrapper to wrap the responses (like StoriesResponse), because I usually need to check some response code.

Hope it helps.

Cheers