拦截器初学

第一步：自定义一个实现了HandlerInterceptor接口的类

重写其中的三个方法

package com.kuang.config;

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

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

/**
 * @author Administrator
 * @description: TODO
 * @date 2021/11/23 11:05
 */
//自定义拦截器

public class MyInterceptor implements HandlerInterceptor {
    /**
     *
     * return true:执行下一个拦截器，放行
     * return false：不执行下一个拦截器
     *
     */
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("==============处理前=============");
        return true;
    }


    //后面两个拦截日志
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("==============处理后=============");
    }

    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("==============清理=============");
    }
}

第二步：在applicationContext.xml中配置拦截器