springboot-项目实战:登录拦截器

承接:springboot-项目实战:登录实现

1 修改登录控制器

在LoginController中添加一条如果登录成功了,就在session中存入用户信息

session.setAttribute("loginUser",userName);

修改后的LoginController.java如下

LoginController.java

package com.lv.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.thymeleaf.util.StringUtils;

import javax.servlet.http.HttpSession;

@Controller
public class LoginController {
    @RequestMapping("/user/login")
    public String login(@RequestParam("userName")String userName, @RequestParam("password") String password, Model model, HttpSession session){
        //具体的业务
        if(!StringUtils.isEmpty(userName) && "123456".equals(password)){
            session.setAttribute("loginUser",userName);
            return "redirect:/main.html";
        }else {
            //告诉用户,你登录失败了
            model.addAttribute("msg","用户名或密码错误");
            return "index";
        }
    }
}

2 在config包下创建一个拦截器

LoginHandlerInterceptor.java

package com.lv.config;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginHandlerInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        //登录成功之后,应该有用户的session
        Object attribute = request.getSession().getAttribute("loginUser");
        if (attribute == null){
            request.setAttribute("msg","访问失败,请先登录");
            request.getRequestDispatcher("/index.html").forward(request,response);
            return false;
        }else {
            return true;
        }
    }
}

3 在自定义的mvc配置类中重写增加拦截器的方法

MyMvcConfig.java

package com.lv.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.LocaleResolver;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class MyMvcConfig implements WebMvcConfigurer {
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("index");
        registry.addViewController("/index.html").setViewName("index");
        registry.addViewController("/main.html").setViewName("dashboard");
    }
    //自定义的国际化组件就生效了
    @Bean
    public LocaleResolver localeResolver(){
        return new MyLocaleResolver();
    }

    //重写增加拦截器方法
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginHandlerInterceptor()).
                addPathPatterns("/**").
                excludePathPatterns("/","/index.html","/user/login","/css/**","/img/**","/js/**");
    }
}

在addInterceptors方法中增加了自己编写的拦截器,并设置拦截所有请求,除了登录页面的请求,登录的请求,和静态资源的请求.

4 修改dashboard.html页面

展示登陆成功后 session 中的用户数据 [[${session.loginUser}]]

<a class="navbar-brand col-sm-3 col-md-2 mr-0" href="http://getbootstrap.com/docs/4.0/examples/dashboard/#">[[${session.loginUser}]]</a>

5 重启程序,进行测试

在未登录状态下访问 main.html

拦截成功,接下来成功登录后,再重新打开一个页面,然后直接访问 main.html

登录成功后换了页面访问main.html,也没有拦截,并且session中存储的信息也成功展示出来,说明拦截器配置成功,实现了登录拦截的功能.