Java jsp文件中的Dispaly servlet arraylist不工作_Java_Jsp_Servlets

Java jsp文件中的Dispaly servlet arraylist不工作

java jsp servlets

Java jsp文件中的Dispaly servlet arraylist不工作,java,jsp,servlets,Java,Jsp,Servlets,我不明白为什么我的jsp页面不会显示我在servlet中创建并添加到会话中的列表。任何帮助都将不胜感激。我已经看了很多答案，但我找不到一个可以解决这个问题的答案我得到的输出是艺术家资料摘要姓Fname国籍出生因此，显示的是表格标题，而不是实际值艺术家班 public class Artist { private String firstname; private String surname; private String nationality;

我不明白为什么我的jsp页面不会显示我在servlet中创建并添加到会话中的列表。任何帮助都将不胜感激。我已经看了很多答案，但我找不到一个可以解决这个问题的答案

我得到的输出是

艺术家资料摘要

姓Fname国籍出生因此，显示的是表格标题，而不是实际值

艺术家班

public class Artist {
     private String firstname;
    private String surname;
    private String nationality;
    private int birthyear;



    public Artist(String F, String S, String N, int I){
        this.firstname=F;
        this.surname=S;
        this.nationality=N;
        this.birthyear=I;

    }

    public String getFirstName(){
        return firstname;
    }



        public String getSurname(){
        return surname;
    }
          public String getNationality(){
        return nationality;
    }

        public int getBirth(){
        return birthyear;
        }  

}

Servlet

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**
 *
 * @author User
 */
@WebServlet(urlPatterns = {"/NewServlet"})
public class NewServlet extends HttpServlet {

    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code>
     * methods.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
        try (PrintWriter out = response.getWriter()) {


            Artist A1 = new Artist("smith", "john", "american", 1999);
            Artist A2 = new Artist("pan", "peter", "canadian", 1956);

            List<Artist> list = new ArrayList<Artist>();
            list.add(A1);
            list.add(A2);

              HttpSession session = request.getSession(); 
        session.setAttribute("info", list);

        RequestDispatcher dispatcher = request.getRequestDispatcher("/newjsp.jsp");
        dispatcher.forward(request,response);

            out.println("<!DOCTYPE html>");
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet NewServlet</title>");            
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet NewServlet at " + request.getContextPath() + "</h1>");
            out.println("</body>");
            out.println("</html>");
        }
    }

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /**
     * Handles the HTTP <code>GET</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     *
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     *
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}

JSP文件

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head></head>
      <body>
        <h1>Summary of artist information</h1>
        <table>
            <thead>
            <tr>
                <th>Surname</th>
                <th>Fname</th>
                <th>nationality</th>
                <th>birth</th>


            </thead>
           <c:forEach items="${art}" var="artist">
                <tr>
                    <td>${artist.Surname}</td>
                    <td>${artist.Firstname}</td>
                    <td>${artist.Nationality}</td>
                    <td>${artist.BirthYear}</td>
                </tr>
                </c:forEach>



        </table>
    </body>
</html>


艺术家资料摘要
姓
Fname
国籍
出生
${艺术家姓氏}
${artist.Firstname}
${艺术家国籍}
${艺术家生日}

您正在使用name

info

在会话变量中设置手动创建的艺术家列表，如下所示

session.setAttribute("info", list);

如果要将此数据显示到jsp上，则需要在

c:forEach

循环中使用名为

info

的相同变量，如下所示

<c:forEach items="${info}" var="artist">
                <tr>
                    <td>${artist.surname}</td>
                    <td>${artist.firstname}</td>
                    <td>${artist.nationality}</td>
                    <td>${artist.birthYear}</td>
                </tr>
  </c:forEach>


${艺术家姓氏}
${artist.firstname}
${艺术家国籍}
${艺术家生日}

还要密切注意上面每个JSTL使用的属性名称、姓氏、名字等。

嘿，伙计，感谢你花时间看这个，我更正了错误，我将它改为你列出的ie items=“${info}”，我更正了变量名称，但我仍然得到相同的输出。你知道为什么吗？