I'm studying iReport Design and I started using Connection at my fillReport. Until then, it's ok. The problem is that, now, I'm using Collection, with the commands: List<Sales> sales = new SalesDAO().getSalesByDate( new SimpleDateFormat("yyyyMMdd").parse("20180101"), new SimpleDateFormat("yyyyMMdd").parse("20180131") );JRDataSource dataSource = new JRBeanCollectionDataSource(sales); In those way, when I try execute, it's show me the following error: