public Page<BlogComment> fetchPageByPostId(Page<BlogComment> page, long postId) {
   return commentDao.fetchByPostId(page, postId);
 }
 public void modifyBlogComment(BlogComment comment) {
   commentDao.update(comment);
 }
 public void removeBlogComment(BlogComment comment) {
   commentDao.delete(comment.getId());
 }
 public void createBlogComment(BlogComment comment) {
   commentDao.insert(comment);
 }