Spring MVC拦截器(Interceptor)的定义和配置过程

package org.springframework.web.servlet;

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

import org.springframework.lang.Nullable;
import org.springframework.web.method.HandlerMethod;

public interface HandlerInterceptor {
	/**
	* 在执行实际储器程序之前，根据返回的boolen判断是否放行
	*/
	default boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception {

		return true;
	}
	/**
	* 执行处理程序之后
	*/
	default void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
			@Nullable ModelAndView modelAndView) throws Exception {
	}
	/**
	* 在完成请求后
	*/
	default void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler,
			@Nullable Exception ex) throws Exception {
	}

}

package com.example.web.interceptor;

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

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

public class MyInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String requestURI = request.getRequestURI();
        System.out.println("请求的路径：" +requestURI);
        long startTime = System.currentTimeMillis();
        request.setAttribute("request::start",startTime);
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        long startTime = (long)request.getAttribute("request::start");
        long processEndTime = System.currentTimeMillis();
        System.out.println("处理程序执行完成耗时："+ (processEndTime-startTime) + "毫秒");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        long startTime = (long)request.getAttribute("request::start");
        long endTime = System.currentTimeMillis();
        System.out.println("从请求到完成响应耗时："+ (endTime-startTime) + "毫秒");
    }
}

@Configuration
@EnableWebMvc
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
    	registry.addInterceptor(new MyInterceptor())
        registry.addInterceptor(new LocaleChangeInterceptor());
        registry.addInterceptor(new ThemeChangeInterceptor()).addPathPatterns("/**").excludePathPatterns("/admin/**");
        registry.addInterceptor(new SecurityInterceptor()).addPathPatterns("/secure/*");
    }
}

<mvc:interceptors>
	<bean class="com.example.web.interceptor.MyInterceptor"/>
    <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/>
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <mvc:exclude-mapping path="/admin/**"/>
        <bean class="org.springframework.web.servlet.theme.ThemeChangeInterceptor"/>
    </mvc:interceptor>
    <mvc:interceptor>
        <mvc:mapping path="/secure/*"/>
        <bean class="org.example.SecurityInterceptor"/>
    </mvc:interceptor>
</mvc:interceptors>