登录功能

登录功能分析

 

代码实现

 LoginServlet

package cn.itcast.travel.web.servlet;

import cn.itcast.travel.domain.ResultInfo;
import cn.itcast.travel.domain.User;
import cn.itcast.travel.service.UserService;
import cn.itcast.travel.service.impl.UserServiceImpl;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.commons.beanutils.BeanUtils;

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;
import java.lang.reflect.InvocationTargetException;
import java.util.Map;

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //1.获取用户名和密码数据
        Map<String, String[]> map = request.getParameterMap();

        //2.封装User对象
        User user = new User();
        try {
            BeanUtils.populate(user, map);
        } catch (Exception e) {
            e.printStackTrace();
        }

        //3.调用Servlet查询
        UserService service = new UserServiceImpl();
        User u = service.login(user);

        ResultInfo info = new ResultInfo();

        //4.判断用户对象是否为null
        if (u == null){
            //用户名或密码错误
            info.setFlag(false);
            info.setErrorMsg("用户名或密码错误");
        }

        //5.判断用户是否激活
        if (u != null && !"Y".equals(u.getStatus())){
            //用户尚末激活
            info.setFlag(false);
            info.setErrorMsg("您尚末激活，请激活");
        }
        //6. 判断登录成功
        if (u != null && "Y".equals(u.getStatus())){
            request.getSession().setAttribute("user", u);//登录成功的标记

            //登录成功
            info.setFlag(true);
        }

        //响应数据
        ObjectMapper mapper = new ObjectMapper();

        //设置编码
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(), info);


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

UserService

    /**
     * 登录方法
     * @param user
     * @return
     */
    User login(User user);

UserServiceImpl

    /**
     * 登录方法
     * @param user
     * @return
     */
    @Override
    public User login(User user) {
        return userDao.findByUsernameAndPassword(user.getUsername(),user.getPassword());
    }

UserDao

    /**
     * 根据用户名和密码查询的方法
     * @param username
     * @param password
     * @return
     */
    User findByUsernameAndPassword(String username, String password);

UserDaoImpl

    /**
     * 根据用户名和密码查询的方法
     * @param username
     * @param password
     * @return
     */
    @Override
    public User findByUsernameAndPassword(String username, String password) {
        User user = null;
        try {
            //1.定义sql
            String sql = "select * from tab_user where username = ? and password = ?";
            //2.执行sql
            user = template.queryForObject(sql, new BeanPropertyRowMapper<User>(User.class), username,password);
        } catch (Exception e) {

        }

        return user;
    }

 

 

 登录前台页面：

login.html

    <script>

        $(function () {
            //1.给登录按钮绑定单击事件
            $("#btn_sub").click(function () {
                //2.发送ajax请求，提交表单数据
                $.post("loginServlet",$("#loginForm").serialize(),function (data) {
                    //data : {flag:false,errorMsg:''}
                    if(data.flag){
                        //登录成功
                        location.href="index.html";
                    }else{
                        //登录失败
                        $("#errorMsg").html(data.errorMsg);
                    }
                });
            });
        });
    </script>

 

 

index页面中用户信息的姓名提示功能

FindUserServlet

package cn.itcast.travel.web.servlet;

import com.fasterxml.jackson.databind.ObjectMapper;

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("/findUserServlet")
public class FindUserServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //从session中获取登录用户
        Object user = request.getSession().getAttribute("user");

        //将user写回客户端
        ObjectMapper mapper = new ObjectMapper();
        //设置编码
        response.setContentType("application/json;charset=utf-8");
        //回写
        mapper.writeValue(response.getOutputStream(),user);


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

header.html头部页面

<script>
    $(function () {
       $.get("findUserServlet",{},function (data) {
           //{uid:1,name:'李四'}
           var msg = "欢迎回来，"+data.name;
           $("#span_username").html(msg);

       }); 
    });

 

 

 

退出登录

什么叫做登录了？session中有user对象

实现步骤：

　　1、访问servlet，将session销毁

　　2、跳转到登录页面

header.html头部页面

            <!-- 登录状态  -->
            <div class="login">

                <span id="span_username"></span>
                <a href="myfavorite.html" class="collection">我的收藏</a>
                <a href="javascript:location.href='exitServlet';">退出</a>
            </div>

ExitServlet

package cn.itcast.travel.web.servlet;

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("/exitServlet")
public class ExitServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //1.销毁session
        request.getSession().invalidate();

        //2.跳转登录页面
        response.sendRedirect(request.getContextPath()+"/login.html");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}