Spring data JPA只查询部分字段问题及解决

@SqlResultSetMapping(name = "EBookInfo",
        classes = @ConstructorResult(targetClass = EBookInfo.class,
                columns = {
                        @ColumnResult(name = "book_id", type = Long.class),
                        @ColumnResult(name = "book_name", type = String.class),
                        @ColumnResult(name = "file_type", type = String.class)
                }))
@NamedNativeQuery(name = "listExpressEbooks",
        query = "select book_id, book_name, file_type from ebook order by update_date desc",
        resultSetMapping = "EBookInfo")
@Entity
@Table(name = "ebook")
public class Ebook {

    private Long bookId;

    private Integer authorId;
    private String authorName;
    private Integer categoryId;
    private String bookName;
    private String subTitle;
    private String tags;
    private String isbn;
    private String edition;
    private Byte bookType;
    private Integer star;
    private Integer downloadCount;
    private Byte status;
    private String fileType;
    private String outline;
    private String introduction;
    private String preface;
    private String cover;
    private Float price;
    private String publisher;
    private String bgColor;
    private String foreColor;
    private String titleColor;
    private String coverBackgroundId;
    private String coverPictureId;
    private Integer coverTemplateId;
    private String coverPictureMode;
    private Integer pageMode;
    private Timestamp requestDate;
    private Timestamp publishDate;
    private Timestamp updateDate;

@Data
public class EBookInfo {
    private Long bookId;
    private String bookName;    
    private String fileType;

    public EBookInfo(Long bookId, String bookName, String fileType) {
        this.bookId = bookId;
        this.bookName = bookName;
        this.fileType = fileType;
    }

}

    @Query(name = "listExpressEbooks", nativeQuery = true)
    public List<EBookInfo> listExpressEbooks();

public List<Blog> selectByYearMonth(String year, String month, int status) {
    String sql = String.format("select new Blog(blog.id, blog.title, blog.abs, blog.createtime) from Blog blog where blog.status = %d and YEAR(createtime) = %s and MONTH(createtime) = %s order by blog.createtime desc", status, year, month);

    //Query query = this.em.createNativeQuery(sql, "ExpressedResult");
    Query query = this.em.createQuery(sql);
    List results = query.getResultList();

    return results;
}

class NativeResultProcessUtils {

        /**
         * tuple转实体对象
         * @param source tuple对象
         * @param targetClass 目标实体class
         * @param <T> 目标实体类型
         * @return 目标实体
         */
        public static <T> T processResult(Tuple source,Class<T> targetClass) {
            Object instantiate = BeanUtils.instantiate(targetClass);
            convertTupleToBean(source,instantiate,null);
            return (T) instantiate;
        }

        /**
         *
         * tuple转实体对象
         * @param source tuple对象
         * @param targetClass 目标实体class
         * @param <T> 目标实体类型
         * @param ignoreProperties 要忽略的属性
         * @return 目标实体
         */
        public static <T> T processResult(Tuple source,Class<T> targetClass,String... ignoreProperties) {
            Object instantiate = BeanUtils.instantiate(targetClass);
            convertTupleToBean(source,instantiate,ignoreProperties);
            return (T) instantiate;
        }

        /**
         * 把tuple中属性名相同的值复制到实体中
         * @param source tuple对象
         * @param target 目标对象实例
         */
        public static void convertTupleToBean(Tuple source,Object target){
            convertTupleToBean(source,target,null);
        }

        /**
         * 把tuple中属性名相同的值复制到实体中
         * @param source tuple对象
         * @param target 目标对象实例
         * @param ignoreProperties 要忽略的属性
         */
        public static void convertTupleToBean(Tuple source,Object target, String... ignoreProperties){
            //目标class
            Class<?> actualEditable = target.getClass();
            //获取目标类的属性信息
            PropertyDescriptor[] targetPds = BeanUtils.getPropertyDescriptors(actualEditable);
            //忽略列表
            List<String> ignoreList = (ignoreProperties != null ? Arrays.asList(ignoreProperties) : null);

            //遍历属性节点信息
            for (PropertyDescriptor targetPd : targetPds) {
                //获取set方法
                Method writeMethod = targetPd.getWriteMethod();
                //判断字段是否可以set
                if (writeMethod != null && (ignoreList == null || !ignoreList.contains(targetPd.getName()))) {
                    //获取source节点对应的属性
                    String propertyName = targetPd.getName();
                    Object value = source.get(propertyName);
                    if(value!=null && ClassUtils.isAssignable(writeMethod.getParameterTypes()[0], value.getClass())) {
                        try {
                            //判断target属性是否private
                            if (!Modifier.isPublic(writeMethod.getDeclaringClass().getModifiers())) {
                                writeMethod.setAccessible(true);
                            }
                            //写入target
                            writeMethod.invoke(target, value);
                        }
                        catch (Throwable ex) {
                            throw new FatalBeanException(
                                "Could not copy property '" + targetPd.getName() + "' from source to target", ex);
                        }
                    }
                }
            }
        }

    }