Передать результат одного запроса в другой - ошибка

package Controller;
 
import Model.Mysql;
import java.io.IOException;
import java.io.PrintWriter;
import java.sql.ResultSet;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
/**
 *
 * @author dante
 */
public class Questions 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");
        PrintWriter out = response.getWriter();
        Mysql mysql = new Mysql();
        String id_theme = request.getParameter("questions");
        String page = "questions.jsp";
        Map<Integer, String> map = new HashMap<Integer, String>();
        try {
            mysql.initConnection();
            ResultSet rss = mysql.QuerySelect("SELECT * FROM questions WHERE id_theme='" + id_theme + "'");
            request.setAttribute("data", rss);
            while (rss.next()) {
                //Add records into data list
                map.put(rss.getInt("id_questions"),rss.getString("question"));
            }
            out.println(map.get(1));
            out.println(map.get(2));
            request.setAttribute("data", map);
            request.setAttribute("id_theme", id_theme);
        } catch (Exception e) {
            e.printStackTrace();
        }
 
        RequestDispatcher dispatcher = request.getRequestDispatcher(page);
        if (dispatcher != null) {
            dispatcher.forward(request, response);
        }
    }
 
    // <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>
}