老师，出了点问题需要帮忙解决

Course类：

package com.andreas.servlet;
 
public class Course {
    private String id; //课程编号
    private String name;//课程名
    private String category;//所属方向
    public Course() {
         
    }
     
    public Course(String id, String name, String category) {
        super();
        this.id = id;
        this.name = name;
        this.category = category;
    }
 
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getCategory() {
        return category;
    }
    public void setCategory(String category) {
        this.category = category;
    }
    @Override
    public String toString() {
        return "课程信息： [课程编号：=" + id + ", 课程名：=" + name + ", 所属方向：" + category + "]";
    }
     
     
     
}

Elservlet ：

package com.andreas.servlet;
 
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 * Servlet implementation class Elservlet
 */
@WebServlet("/Elservlet")
public class Elservlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
        
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Elservlet() {
        super();
        // TODO Auto-generated constructor stub
    }
 
    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//      String level = request.getParameter("level");
        Course cou = new Course();
        cou.setId("001");
        cou.setName("人工智能");
        cou.setCategory("计算机科学");
        request.setAttribute("course", cou);
        request.getRequestDispatcher("/Eljsp.jsp").forward(request, response);
    }
 
}

Eljsp：

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" import="com.andreas.servlet.Course"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Eljsp</title>
</head>
<body>
<%-- <%
    Course co = (Course)request.getAttribute("course");
    out.println("<h1>" + co.getId() + "</h1>");
    out.println("<h1>" + co.getName() + "</h1>");
%> --%>
    <p>课程编号：${requestScope.course.id}</p>
    <p>课程名：${requestScope.course.name}</p>
    <p>所属方向：${requestScope.course.category}</p>
    <p>${course}</p>
</body>
</html>

urljsp：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>urljsp</title>
</head>
<body>
<h1>${param.level}</h1>
</body>
</html>