public class User implements Serializable {private int id;private  String uname;private String password;private String sex;private int age;private String birthday;
}

package com.lin.servlet;import com.lin.pojo.User;
import com.lin.service.LoginService;
import com.lin.service.impl.LoginServiceImpl;import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;/*** 用户登录 操作*/
public class UserLoginServlet extends HttpServlet {@Overrideprotected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//设置请求响应编码格式req.setCharacterEncoding("utf-8");resp.setContentType("text/html;charset=utf-8");//接收请求信息String uname = req.getParameter("uname");String password = req.getParameter("password");//处理请求信息调用service层LoginService service = new LoginServiceImpl();User user = service.UserLogin(uname, password);HttpSession session = req.getSession();if (user !=null){session.setAttribute("user",user);resp.sendRedirect("/main.jsp");}else {session.setAttribute("error","登录失败");resp.sendRedirect("/login.jsp");}}
}

package com.lin.service;import com.lin.pojo.User;public interface LoginService {/*** 用户登录* @param uname 用户名* @param password 密码* @return*/User UserLogin(String uname, String password);
}

package com.lin.service.impl;import com.lin.mapper.UserMapper;
import com.lin.pojo.User;
import com.lin.service.LoginService;
import com.lin.util.MyBatisUtil;
import org.apache.ibatis.session.SqlSession;public class LoginServiceImpl implements LoginService {@Overridepublic User UserLogin(String uname, String password) {SqlSession session = MyBatisUtil.getSession();UserMapper mapper = session.getMapper(UserMapper.class);User user = mapper.userLogin(uname, password);session.close();if (user!=null){return user;}else {return null;}}
}

package com.lin.mapper;import com.lin.pojo.User;
import org.apache.ibatis.annotations.Param;public interface UserMapper {/*** 用户登录* @param uname 用户名* @param password 密码* @return*/User userLogin(@Param("uname") String uname ,@Param("password") String password);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.lin.mapper.UserMapper"><select id="userLogin" resultType="User" parameterType="User">select * from t_user where uname=#{uname} and pwd=#{password};</select>
</mapper>

public class UserOutServlet extends HttpServlet {@Overrideprotected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {//设置求情响应编码req.setCharacterEncoding("utf-8");resp.sendRedirect("text/html;charset=utf-8");//处理请求信息 获取sessionHttpSession session = req.getSession();//销毁sessionsession.invalidate();//响应处理结果(重定向)resp.sendRedirect("/login.jsp");}
}