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.springframework.web.servlet.HandlerInterceptor; import org.springframework.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, Object 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, Object o, ModelAndView modelAndView) throws Exception { LOGGER.info("1、postHandle"); } @Override public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception { LOGGER.info("1、afterCompletion"); } }

2）TwoInterceptor 拦截器

import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.web.servlet.HandlerInterceptor; import org.springframework.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, Object 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, Object o, ModelAndView modelAndView) throws Exception { LOGGER.info("2、postHandle"); } @Override public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object 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.springframework.context.annotation.Configuration; import org.springframework.web.servlet.config.annotation.InterceptorRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurer; /** * Web配置文件 */ @Configuration public 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.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; @RestController public 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/reqUrl intercept.TwoInterceptor : 2、url==http://127.0.0.1:8005/reqUrl intercept.TwoInterceptor : 2、postHandle intercept.OneInterceptor : 1、postHandle intercept.TwoInterceptor : 2、afterCompletion intercept.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