package com.demo.common.interceptor;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.web.servlet.HandlerInterceptor;

import org.springframework.web.servlet.ModelAndView;

public class MyInterceptor implements HandlerInterceptor{

    Logger logger = LoggerFactory.getLogger(MyInterceptor.class);

    @Override

    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)

            throws Exception {

        logger.info("preHandle :" +request.getContextPath());

        HttpSession session = request.getSession();

        if (session.getAttribute("user") != null)

            return true;

        // 跳转登录

        String url = request.getContextPath() + "/login";

        response.sendRedirect(url);

        return true;

    }

    @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 {

    }

}

package com.demo.common.interceptor;

import org.springframework.context.annotation.Configuration;

import org.springframework.web.servlet.config.annotation.InterceptorRegistry;

import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration

public class AddInterceptor extends WebMvcConfigurerAdapter{

    public void addInterceptors(InterceptorRegistry registry){

        registry.addInterceptor(new MyInterceptor())

        .addPathPatterns("/**")

        .excludePathPatterns("/login")

        .excludePathPatterns("/loginPost");

    }

}