编辑代码

package concroller;

import java.io.IOException;
import javax.servlet.*;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import dao.UserDAO;
import model.User;

@WebServlet("/login")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) 
            throws ServletException, IOException {
        
        String userid = request.getParameter("userid");
        String password = request.getParameter("password");
        
        UserDAO userDao = new UserDAO();
        User user = userDao.login(userid, password);
        
        if (user != null) {
            HttpSession session = request.getSession();
            session.setAttribute("currentUser", user);
            
            // 根据角色重定向到不同页面
            switch (user.getRole()) {
                case "admin":
                    response.sendRedirect("admin/dashboard.jsp");
                    break;
                case "teacher":
                    response.sendRedirect("teacher/dashboard.jsp");
                    break;
                case "student":
                    response.sendRedirect("student/dashboard.jsp");
                    break;
                default:
                    response.sendRedirect("login.jsp?error=1");
            }
        } else {
            response.sendRedirect("login.jsp?error=1");
        }
    }
}