1、首先我们需要创建interceptor并实现springMVC中的HandlerInterceptor

package com.example.cybg.web.intercepter;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 {@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {System.out.println(request.getHeader("token"));return false;}@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {System.out.println("请求拦截后");}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {System.out.println("请求处理完成后");}}

2、我们需要创建拦截器对应的配置类

package com.example.cybg.config;import com.example.cybg.web.intercepter.MyInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;@Configuration
public class WebConfig implements WebMvcConfigurer {@Overridepublic void addInterceptors(InterceptorRegistry registry) {//这种方式会拦截所有请求registry.addInterceptor(new MyInterceptor());//这种方式会拦截指定的请求
//        registry.addInterceptor(new MyInterceptor()).addPathPatterns("/helloInterceptor");}
}

3、这样一个后端拦截器就配置好了，快去动手发个请求试试吧。