从 Eclipse IDE在Tomcat10.0.10服务器上运行我的 JAVA Servlet 程序时，我遇到了以下问题。我试图从项目属性中更改服务器，并再次清理并重新启动服务器，但同样的错误即将到来。这是我的文件结构和错误的图片 -
错误图像 -
这是服务器控制台屏幕截图 -
servlet 的代码是 -
package net.javaguides.usermanagement.web;
import java.io.IOException;
import java.sql.SQLException;
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 net.javaguides.usermanagement.dao.UserDAO;
import net.javaguides.usermanagement.model.User;
import java.util.*;
@WebServlet("/")
public class UserServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
private UserDAO userDAO;
/**
* Default constructor.
*/
public UserServlet() {
this.userDAO=new UserDAO();
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doGet(request, response);
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String action = request.getServletPath();
switch(action) {
case "/new":
showNewForm(request,response);
break;
case "/insert":
try {
insertUser(request,response);
} catch (IOException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
break;
case "/delete":
try {
deleteUser(request,response);
} catch (IOException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
break;
case "/edit":
showEditForm(request,response);
break;
case "/update":
try {
updateUser(request,response);
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
break;
default:
try {
listUser(request,response);
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ServletException e) {
e.printStackTrace();
}
break;
}
}
private void listUser(HttpServletRequest request, HttpServletResponse response) throws SQLException, IOException, ServletException {
List<User> listUser=userDAO.selectAllUsers();
request.setAttribute("listUser", listUser);
RequestDispatcher dispatcher = request.getRequestDispatcher("user-list.jsp");
dispatcher.forward(request, response);
}
private void updateUser(HttpServletRequest request, HttpServletResponse response) throws SQLException, IOException {
int id=Integer.parseInt(request.getParameter("id"));
String name=request.getParameter("name");
String email=request.getParameter("email");
String country=request.getParameter("country");
User user=new User(id,name,email,country);
userDAO.updateUser(user);
response.sendRedirect("list");
}
private void deleteUser(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException {
int id=Integer.parseInt(request.getParameter("id"));
userDAO.deleteUser(id);
response.sendRedirect("list");
}
private void showEditForm(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
int id=Integer.parseInt(request.getParameter("id"));
User existingUser=userDAO.selectUser(id);
RequestDispatcher dispatcher = request.getRequestDispatcher("user-form.jsp");
request.setAttribute("user",existingUser);
dispatcher.forward(request, response);
}
private void showNewForm(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
RequestDispatcher dispatcher = request.getRequestDispatcher("user-form.jsp");
dispatcher.forward(request, response);
}
private void insertUser(HttpServletRequest request, HttpServletResponse response) throws IOException, SQLException {
String name=request.getParameter("name");
String email=request.getParameter("email");
String country=request.getParameter("country");
User newUser=new User(name,email,country);
userDAO.insertUser(newUser);
response.sendRedirect("list");
}
}
谁能帮我解决这个问题...