springboot

myconfig

package com.gm.config;

import com.gm.common.MyInterceptor;
import org.mybatis.spring.boot.autoconfigure.ConfigurationCustomizer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
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 MyConfig {


    @Bean
    public WebMvcConfigurer webMvcConfigurer(){
        WebMvcConfigurer webMvcConfigurer=new WebMvcConfigurer() {
            @Override
            public void addViewControllers(ViewControllerRegistry registry) {
                registry.addViewController("/").setViewName("login");
                registry.addViewController("/login.html").setViewName("login");
                registry.addViewController("/main.html").setViewName("main");

            }
            @Override
            public void addInterceptors(InterceptorRegistry registry) {
                registry.addInterceptor(new MyInterceptor())
                        .addPathPatterns("/**")
                        .excludePathPatterns("/login.html","/","/login")
                        .excludePathPatterns("/css/**")
                        .excludePathPatterns("/images/**")
                        .excludePathPatterns("/fonts/**")
                        .excludePathPatterns("/js/**")
                        .excludePathPatterns("/webjars/**");
            }
        };
        return webMvcConfigurer;
    }
}

MyInterceptor

package com.gm.common;

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * @Author Administrator
 * @Date 2020/6/4 13:45
 **/

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        Object user = request.getSession().getAttribute("user");
        if (user!=null){
            //登录成功，放行
            return true;
        }else {
            //未登录 返回登录页面 并给出错误提示
            request.setAttribute("msg","无权限，请先登录！");
            //一：request
            request.getRequestDispatcher("/login.html").forward(request,response);
            //二：重定向
//            response.sendRedirect("/");
            return false;
        }
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}