String backtime=“2020-06-13”
SimpleDateFormat ft = new SimpleDateFormat("yyyy-MM-dd");
try {
Date date = ft.parse(backtime);//一定要放到try里面哟
ApplySeal obj=appsealDao.selectById(id);
obj.setBacktime(date);
}catch(Exception e) {
e.printStackTrace();
return Msg.fail();
}