《黑吗旅游网》综合案例五 登录

登录功能

分析：

 

 Servlet层：

@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //验证码的校验
        String check = request.getParameter("check");
        //从session中获取验证码
        HttpSession session = request.getSession();
        String checkcode_server = (String) session.getAttribute("CHECKCODE_SERVER");
        session.removeAttribute("CHECKCODE_SERVER");//保证验证码只使用一次
        //比较
        if (checkcode_server==null || !checkcode_server.equalsIgnoreCase(check)){
            //验证码错误
            ResultInfo info = new ResultInfo();
            //注册失败
            info.setFlag(false);
            info.setErrorMsg("验证码错误!");
            //将info对象序列化json并且写回客户端
            ObjectMapper mapper = new ObjectMapper();
            String json = mapper.writeValueAsString(info);
            //将json数据写回客户端
            //设置content-type
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(json);
            return;
        }
        
        //获取用户名和密码数据
        Map<String, String[]> map = request.getParameterMap();
        //封装user对象
        User user = new User();
        try {
            BeanUtils.populate(user,map);
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
        //调用Service查询
        UserServiceImpl service = new UserServiceImpl();
        User u = service.login(user);
　　　　　request.getSession().setAttribute("user",u)
        ResultInfo info = new ResultInfo();
        //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");
        }
        //判断用户是否激活
        if (u!=null && !"Y".equals(u.getStatus())){
            //用户尚未激活
            info.setFlag(false);
            info.setErrorMsg("您尚未激活，请激活");
        }
        //判断登录成功
        if (u!=null && "Y".equals(u.getStatus())){
            //登录成功
            info.setFlag(true);
        }
        //响应数据
        ObjectMapper mapper = new ObjectMapper();
        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);
    }
}

Service和Dao层：

UserService：添加一个方法

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：添加一个方法

User findByUsernameAndPassword(String username, String password);

UserDaoImpl：

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

        }
        return user;
    }

前台 login 页面：

给登录按钮添加一个id

 

 

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

 

用户姓名提示信息功能：

 

header.html：

将span内容删除添加一个id

<!-- 头部 start -->
<script>
    $(function () {
        $.get("findUserServlet",{},function (data) {
            var msg = "欢迎回来,"+data.name;
            $("#span_username").html(msg);
        });
    });
</script>

FindUserServlet:

 

@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();
        response.setContentType("application/json;charset=utf-8");
        mapper.writeValue(response.getOutputStream(),user);
    }

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

进行登录（如果还是admin可以试着把缓存进行清理）

 

 退出登录

 访问Servlet，将session销毁

跳转到登录页面

header.html：在header页面中编写退出

 

 ExitServlet：

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