一、拦截器简介

1、拦截器定义

拦截器，请求的接口被访问之前，进行拦截然后在之前或之后加入某些操作。拦截是AOP的一种实现策略。 拦截器主要用来按照指定规则拒绝请求。

2、拦截器中应用

Token令牌验证请求数据校验用户权限校验放行指定接口

二、SpringBoot2.0拦截器用法

1、编写两个拦截器

自定义类实现HandlerInterceptor接口
1）OneInterceptor 拦截器

import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.spring work.web.servlet.HandlerInterceptor;import org.spring work.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 拦截器一 */public class OneInterceptor implements HandlerInterceptor { private static final Logger LOGGER = LoggerFactory.getLogger(OneInterceptor.class.getName()); @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response,   o) throws Exception { String url =String.valueOf(request.getRequestURL()) ; LOGGER.info("1、url=="+url); // 放开拦截 return true; } @Override public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,   o, ModelAndView modelAndView) throws Exception { LOGGER.info("1、postHandle"); } @Override public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,   o, Exception e) throws Exception { LOGGER.info("1、afterCompletion"); }}

2）TwoInterceptor 拦截器

import org.slf4j.Logger;import org.slf4j.LoggerFactory;import org.spring work.web.servlet.HandlerInterceptor;import org.spring work.web.servlet.ModelAndView;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 拦截器二 */public class TwoInterceptor implements HandlerInterceptor { private static final Logger LOGGER = LoggerFactory.getLogger(TwoInterceptor.class.getName()); @Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response,   o) throws Exception { String url =String.valueOf(request.getRequestURL()) ; LOGGER.info("2、url=="+url); // 放开拦截 return true; } @Override public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,   o, ModelAndView modelAndView) throws Exception { LOGGER.info("2、postHandle"); } @Override public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse,   o, Exception e) throws Exception { LOGGER.info("2、afterCompletion"); }}

2、Web配置文件中注入拦截器

import com.boot.intercept.intercept.OneInterceptor;import com.boot.intercept.intercept.TwoInterceptor;import org.spring work.context.annotation.Configuration;import org.spring work.web.servlet.config.annotation.InterceptorRegistry;import org.spring work.web.servlet.config.annotation.WebMvcConfigurer;/** * Web配置文件 */@Configurationpublic class WebMvcConfig implements WebMvcConfigurer { public void addInterceptors(InterceptorRegistry registry) { // 拦截所有路径 // 注册自定义两个拦截器 registry.addInterceptor(new OneInterceptor()).addPathPatterns("/**"); registry.addInterceptor(new TwoInterceptor()).addPathPatterns("/**"); }}

3、编写测试接口

import org.spring work.web.bind.annotation.RequestMapping;import org.spring work.web.bind.annotation.RestController;@RestControllerpublic class InterceptController { @RequestMapping("/reqUrl") public String reqUrl (){ return "success" ; }}

4、访问测试接口

日志输出内容如下

intercept.OneInterceptor : 1、url==http://127.0.0.1:8005/reqUrlintercept.TwoInterceptor : 2、url==http://127.0.0.1:8005/reqUrlintercept.TwoInterceptor : 2、postHandleintercept.OneInterceptor : 1、postHandleintercept.TwoInterceptor : 2、afterCompletionintercept.OneInterceptor : 1、afterCompletionla

拦截器的拦截顺序，是按照Web配置文件中注入拦截器的顺序执行的。

三、源代码地址

GitHub地址：知了一笑https://github.com/cicadasmile码云地址：知了一笑https://gitee.com/cicadasmile