public List<CommentInfo> listAll() throws Exception {
   List<CommentInfo> lst = new ArrayList<CommentInfo>();
   String sql = "select * from Comment";
   ResultSet rs = this.db.getSQLResult(sql);
   while (rs.next()) {
     CommentInfo info = new CommentInfo();
     info.id = rs.getInt("Id");
     info.name = rs.getString("Name");
     info.date = rs.getString("Date");
     info.comment = rs.getString("Comment");
     lst.add(info);
   }
   return lst;
 }