springmvc 配置拦截器

package com.aaa.zxf.interceptor;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

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

/**
 *  一、 springmvc  配置拦截器
 *    1.1 创建在 web层下，新建一个interceptor 包。
 *    1.2 新建一个类，继承WebMvcConfigurerAdapter
 *    1.3 重写addInterceptors  这个方法
 *        在方法中，放入私有的方法，  设置需要拦截的路径。
 *
 *    1.4 定义一个私有的方法  实现 HandlerInterceptor 中的方法。
 *        返回一个HandlerInterceptor
 *
 * 二、 添加     @SpringBootApplication
 *
 */
@SpringBootApplication
public class LoginInterceptor extends WebMvcConfigurerAdapter {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //  拦截的路径
        registry.addInterceptor(loginIntercepor()).addPathPatterns("/**");
    }

    /**
     * 返回一个   HandlerInterceptor 类型
     * @return
     */
    private  HandlerInterceptor loginIntercepor(){
        HandlerInterceptor handlerInterceptor=new HandlerInterceptor() {
            @Override
            public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
                System.out.println("拦截器，被访问了！");
                httpServletRequest.getSession(false);
                return true;
            }

            @Override
            public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

            }

            @Override
            public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {

            }
        };
        return  handlerInterceptor;
    }
}