Request resource is not available in servlet

Question

i'm learning make crud java web using servlet. When i access url for list data is success, but when access create data, i get an error in browser like this

When i check in netbeans, error displaying

com.sun.tools.javac.code.ClassFinder$BadClassFile: bad class file: HttpServlet.class
variable of type 'java.lang.String' cannot have a constant value, but has one specified
Please remove or make sure it appears in the correct subdirectory of the classpath.....
Caused: java.io.IOException.......

This is my code in UserServlet file

package user;

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

import jakarta.servlet.RequestDispatcher;
import jakarta.servlet.ServletException;
import jakarta.servlet.annotation.WebServlet;
import jakarta.servlet.http.HttpServlet;
import jakarta.servlet.http.HttpServletRequest;
import jakarta.servlet.http.HttpServletResponse;

@WebServlet("/users")
public class UserServlet extends HttpServlet {
   private UserDAO userDAO;

   @Override
   public void init() {
      userDAO = new UserDAO();
   }

   @Override
   protected void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
      doGet(request, response);
   }

   @Override
   protected void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
      String action = request.getServletPath();

      try {
        switch (action) {
            case "/create" -> createForm(request, response);
            default -> listUser(request, response);
        }
      } catch (SQLException ex) {
        throw new ServletException(ex);
      }
   }

   private void listUser(HttpServletRequest request, HttpServletResponse response)
   throws SQLException, IOException, ServletException {
      List <User> listUser = userDAO.getAllUser();
      request.setAttribute("listUser", listUser);
      RequestDispatcher dispatcher = request.getRequestDispatcher("user/list.jsp");
      dispatcher.forward(request, response);
   }

   private void createForm(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
      RequestDispatcher dispatcher = request.getRequestDispatcher("user/form.jsp");
      dispatcher.forward(request, response);
   }
}

How to solving that?