How to import a class from default package to jsp

Question

I'm trying to pass a arrayList from servlet to jsp.

This is code from servlet

ArrayList<User> users = UserCollection.getInstance().getArray(); 
        HttpSession session=request.getSession();
        session.setAttribute("list", users); 
        response.sendRedirect("ListProfils.jsp");

This is code in jsp

<center>
        <table style="width:60%" id="t01">
          <tr background-color: #012e5e;>
            <th>Email</th>
            <th>Phone Number</th>
            <th>City</th>
            <th>Address</th>
          </tr>
          <%@page import="java.util.ArrayList"%>

          <% 
          ArrayList<User> val=(ArrayList)request.getSession().getAttribute("list");

          for (User user : val) { %>
            <tr>
            <td><%out.println(user.getEmail());%></td>
            <td><%out.println(user.getPhoneNumber());%></td>
            <td><%out.println(user.getCity());%></td>
            <td><%out.println(user.getAddress());%></td>
          </tr>
         <% }

          %>

        </table>
    </center>   

But when i try to run code тhe following error is displayed

An error occurred at line: [37] in the jsp file: [/ListProfils.jsp]
User cannot be resolved to a type
34:           <%@page import="java.util.ArrayList"%>
35:           
36:           <% 
37:           ArrayList<User> val=(ArrayList)request.getSession().getAttribute("list");
38:           
39:           for (User user : val) { %>
40:             <tr>


An error occurred at line: [39] in the jsp file: [/ListProfils.jsp]
User cannot be resolved to a type
36:           <% 
37:           ArrayList<User> val=(ArrayList)request.getSession().getAttribute("list");
38:           
39:           for (User user : val) { %>
40:             <tr>
41:             <td><%out.println(user.getEmail());%></td>
42:             <td><%out.println(user.getPhoneNumber());%></td>

I read in google for this bug, and I had to import my class User. But he is in a default package and i dont know how to import him. Please help me