Servlet not displaying data obtained from dao

Question

in dao

public class DAO {

    Connection conn = null;
    PreparedStatement ps = null;
    ResultSet rs = null;

    public List<Product> getAllProduct() {
        List<Product> list = new ArrayList<>();
        String query = "select * from product";
        try {
            conn = new DBContext().getConnection();
            ps = conn.prepareStatement(query);
            rs = ps.executeQuery();
            while (rs.next()) {
                list.add(new Product(rs.getInt(1),
                        rs.getString(2),
                        rs.getString(3),
                        rs.getDouble(4),
                        rs.getString(5),
                        rs.getString(6)));
            }
        } catch (Exception e) {
        }
        return list;
    }

check dao

public static void main(String[] args) {
        DAO dao = new DAO();
        List<Product> list = dao.getAllProduct();

        for (Category o : list) {
            System.out.println(o);
        }
    }

i checked, it ran successfully

in servlet

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        
        DAO dao = new DAO();
        List<Product> list = dao.getAllProduct();
        
        
        request.setAttribute("listP", list);
        request.getRequestDispatcher("Home.jsp").forward(request, response);
       
    }

and i check in Home.jsp

<c:if test="${empty requestScope.listP}">
    <p>List null</p>
</c:if>

the ouput is list null

How can I fix this, I use Apache NetBeans 17,apache-tomcat-10.1.17, jdk-17.0.9_windows-x64_bin