package com.example.mongodemo.config;

import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

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

/**
 * @Author lyr
 * @create 2020/3/24 1:18
 * 拦截器
 * 要在 webMvcConfiguration注册
 */
@Slf4j
@Component
public class WebInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        log.info("开始");
        //打印对应 处理请求的 Controller类
        log.info(((HandlerMethod)handler).getBean().getClass().getName());
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        log.info("运行中");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        log.info("结束");
        //抛出异常的话 会有 ex参数
    }
}

然后 要在配置上面注册一下这个拦截器

package com.example.mongodemo.config;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

/**
 * @Author lyr
 * @create 2020/3/23 19:53
 */

@Configuration //标注时配置类
public class MvcConfig implements WebMvcConfigurer {

    @Autowired
    private WebInterceptor interceptor;
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(interceptor);
    }

    @Bean
    public MvcConfig MyMvcConfig() {
        MvcConfig mvcConfig = new MvcConfig() {


            @Override
            public  void addResourceHandlers(ResourceHandlerRegistry registry) {
                registry.addResourceHandler("swagger-ui.html")
                        .addResourceLocations("classpath:/META-INF/resources/");
                registry.addResourceHandler("/webjars/**")
                        .addResourceLocations("classpath:/META-INF/resources/webjars/");
            }
        };
        return mvcConfig;

    }
}