JSP HTTP Status 500错误

打算分开两种情况来验证两个数据库中不同的账号密码，出错了但并不清楚是哪里的问题

package web;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import dao.AdminDao;
import dao.UserDao;
import model.Admin;
import model.User;


@WebServlet("/LoginServlet")
public class LoginServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
 
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		response.setContentType("text/html;charset=utf-8");
		request.setCharacterEncoding("utf-8");
			String account=request.getParameter("account");
			String password=request.getParameter("password");
			String type = request.getParameter("type");
			
			Admin admin=new Admin();
			if (type=="teacher"){
				admin.setAaccount(account);
				admin.setApassword(password);
			//	admin=login.login(admin);
				AdminDao adminDao=new AdminDao();
				try{
					admin=adminDao.login(admin);
					if(admin !=null){
						System.out.println(admin.getAaccount());
						response.sendRedirect("admin/welcome.jsp");	
					}else{
						request.setAttribute("error", "输入有误");
						request.getRequestDispatcher("login.jsp").forward(request, response);
					}
				}catch(Exception e){
					e.printStackTrace();
				}		
		}else{		
			User user=new User();
			user.setUaccount(account);
			user.setUpassword(password);
		//	admin=login.login(admin);
			UserDao userDao=new UserDao();
			try{
				user=userDao.login(user);
				if(user !=null){
					System.out.println(user.getUaccount());
					response.sendRedirect("admin/welcome.jsp");
				}else{
					request.setAttribute("error", "输入有误");
					request.getRequestDispatcher("login.jsp").forward(request, response);
				}
			}catch(Exception e){
				e.printStackTrace();
			}
		}
		
	        }
		protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
			
			doGet(request, response);
		}

	}

如有帮助，望采纳！

错误信息提示是User类找不到,排查步骤如下:

1、确定User这个类是否存在

2、如果User存在,重启服务再重试看是否能解决(这个错误就是加载不到User类)

有这个类的，重启试了也没啥用