BookObject.java

@IgnoreExtraProperties
public class BookObject extends ArrayList<BookObject> {
    public String title;
    public String subtitle;
    public String authors;
    public String imageURL;
    private String pushId;


    public BookObject(){}
    public BookObject(String Title , String Subtitle , String[] Authors , String ImageURL)
    {
        this.title = Title;
        this.subtitle = Subtitle;
        this.authors = ConvertToString(Authors);
        this.imageURL = ImageURL;
    }
    @Exclude
    public String ConvertToString(String[] arr)
    {
        StringBuilder builder = new StringBuilder();

            for(int i = 0; i < arr.length; i++)
            {
                if(i == arr.length - 1) {
                    builder.append(arr[i]);
                    builder.append(".");
                }
                else
                {
                    builder.append(arr[i]);
                    builder.append(",");
                }
            }

        String str = builder.toString();
        return str;

    }
    public String getTitle()
    {
        return title;
    }
    public String getSubtitle()
    {
        return subtitle;
    }
    public String getAuthors()
    {
        return authors;
    }
    public String getImageURL(){ return imageURL;}
    public String getPushId() {return pushId;}
    public void setPushId(String pushId) {this.pushId = pushId;}



    @Exclude
    public Map<String, Object> toMap() {
     HashMap<String, Object> result = new HashMap<>();
     result.put("title", title);
     result.put("subtitle", subtitle);
     result.put("authors", authors);
     result.put("imageURL", imageURL);


         return result;
         }


}

`@IgnoreExtraProperties
public class BookObject extends ArrayList {
public String Title;
public String Subtitle;
public String Authors;
public String ImageURL;
@exclude
private String pushId;

public BookObject(){}
public BookObject(String Title , String Subtitle , String[] Authors , String ImageURL)
{
    this.Title = Title;
    this.Subtitle = Subtitle;
    this.Authors = ConvertToString(Authors);
    this.ImageURL = ImageURL;
}

@Exclude
public String ConvertToString(String[] arr)
{
    StringBuilder builder = new StringBuilder();

        for(int i = 0; i < arr.length; i++)
        {
            if(i == arr.length - 1) {
                builder.append(arr[i]);
                builder.append(".");
            }
            else
            {
                builder.append(arr[i]);
                builder.append(",");
            }
        }

    String str = builder.toString();
    return str;

}
public String getTitle()
{
    return Title;
}
public String getSubtitle()
{
    return Subtitle;
}
public String getAuthors()
{
    return Authors;
}
public String getImageURL(){ return ImageURL;}

@exclude
public String getPushId() {
return pushId;
}

@exclude
public void setPushId(String pushId) {
this.pushId = pushId;
}
@exclude
public Map<String, Object> toMap() {
HashMap<String, Object> result = new HashMap<>();
result.put("title", Title);
result.put("subtitle", Subtitle);
result.put("authors", Authors);
result.put("imageURL", ImageURL);

     return result;
     }

}`