how to insert into model in ActiveAndroid?

I know how to insert string into model in ActiveAndroid. like this.

Book book = new Book();
book.title = "Book"; 
book.save();

I could understood the way insert "String" or "int" only. then, how can I insert into model?

And when do I have to describe "save"? I think describe in Activity. However,in this code, describe in Model and Activity.

Please tell me how to resolve this problem.

 public static void jsonParse() {

new Delete().from(Book.class).execute();
ActiveAndroid.beginTransaction();

try {
    AndroidTestActivity.mContext = app.getContext();

    AssetManager assetManager = mContext.getAssets();

    InputStream inputStream = assetManager.open(FILE_NAMES);

    JsonReader jsonReader = new JsonReader(new InputStreamReader(inputStream));
    Gson gson = new Gson();
    JsonParser parser = new JsonParser();
    JsonArray jArray = parser.parse(jsonReader).getAsJsonArray();

    Book book = new Book();
    /** how can I insert into model? */
    book.title = 
    book.author = 
    book.publisher = 
    book.releaseDate = 

    book.save();

} catch (IOException e) {
    e.printStackTrace();
}
finally {
    ActiveAndroid.setTransactionSuccessful();
}
ActiveAndroid.endTransaction();

}

---

@Table(name = "Book")
public class Book extends Model {
    private static final String TAG = Book.class.getSimpleName();

    @Column(name = "title")
    public String title;

    @Column(name = "author")
    public String author;

    @Column(name = "publisher")
    public String publisher;

    @Column(name = "release_date")
    public String releaseDate;

    public Book() {
        super();
    }
    public Book(String title, String author, String publisher, String date) {
        super();
        this.title = title;
        this.author = author;
        this.publisher = publisher;
        this.releaseDate = date;
    }

    public static Book fromJson(JSONObject jsonObject){
        Book b = new Book();

        try{
            b.title = jsonObject.getString("title");
            b.author = jsonObject.getString("author");
            b.publisher = jsonObject.getString("publisher");
            b.releaseDate = jsonObject.getString("release_date");
            b.save();
        }catch (JSONException e) {
            e.printStackTrace();
            return null;
        }
        //return new object
        return b;
    }
}