LoginServlet类

import cn.itcast.dao.UserDao;
import cn.itcast.domain.User;

	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 java.io.IOException;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
//1.设置编码
req.setCharacterEncoding("utf-8");
//2.获取请求参数
String username = req.getParameter("username");
String password = req.getParameter("password");
//3.封装user对象
User loginUser = new User();
loginUser.setUsername(username);
loginUser.setPassword(password);

	        //4.调用UserDao的login方法
	        UserDao dao = new UserDao();
	        User user = dao.login(loginUser);
	
	        //5.判断user
	        if(user == null){
	            //登录失败
	            req.getRequestDispatcher("/failServlet").forward(req,resp);
	        }else{
	            //登录成功
	            //存储数据
	            req.setAttribute("user",user);
	            //转发
	            req.getRequestDispatcher("/successServlet").forward(req,resp);
	        }
	
	    }
	
	    @Override
	    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
	        this.doGet(req,resp);
	    }
	}