这个user.getUsername()的值是null啊!为何无法传值呢?求解!
public String login(){
UsersDAO udao = new UsersDAOImpl();
if(!udao.usersLogin(user)){
session.setAttribute("loginUserName", user.getUsername());
System.out.print(user.getUsername());
return "login_success";
}else{
return "login_failure";