1.POM依赖

 <!--过滤、监听、拦截-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-aop</artifactId>
        </dependency>

2.新建WebConfig

package com.spring.boot.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.config.annotation.InterceptorRegistration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {

        InterceptorRegistration interceptorRegistration = registry.addInterceptor(new MyInterceptor());
        /*同一异常和无界面*/
        interceptorRegistration.excludePathPatterns("/error");
        interceptorRegistration.excludePathPatterns("/login");
//        interceptorRegistration.excludePathPatterns("/**");
//        interceptorRegistration.excludePathPatterns("/index");
        interceptorRegistration.addPathPatterns("/**");


    }

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {

        //需要配置1：需要告知系统，这是要被当成静态文件的！
        //第一个方法设置访问路径前缀，第二个方法设置资源路径
        registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");
    }

    private class MyInterceptor implements HandlerInterceptor {

        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {

            System.out.println("在控制器执行前调用 ");
            Object admin = request.getSession().getAttribute("admin");
            if (admin == null) {
                System.out.println("当前用户未登录!");
                response.sendRedirect( "/login");
                return false;
            }
            System.out.println("当前用户已登录，登录的用户名为： " + admin);
            return true;
        }

        @Override
        public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {
            //controller方法处理完毕后，调用此方法
            System.out.println("在后端控制器执行后调用 ");
        }

        @Override
        public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {
            //页面渲染完毕后调用此方法
            System.out.println("整个请求执行完成后调用 ");
        }
    }
}

3.需要Controller中重写login

 @RequestMapping(value = "/login")
    public String admin(){

        return "login";
    }

注：自己稍微梳理一下