1.定义一个拦截器类，实现HandlerInterceptor接口

创建一个Interceptor类实现HandlerInterceptor接口，重写preHandle()，postHandle()，afterCompletion() 三个方法
如下代码，我们就创建了一个Spring的拦截器

/**
 * @author rick
 */
@Component
public class EasyLogControllerInterceptor implements HandlerInterceptor {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    /**
     * 在controller调用之前执行
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
            throws Exception {
        logger.info(request.getRequestURI()+"preHandle开始执行");
        return true;
    }

    /**
     * 在controller调用中执行
     */
    @Override
    public void postHandle(
            HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView)
            throws Exception {
        logger.info(request.getRequestURI()+"postHandle开始执行");
    }

    /**
     * 在controller调用后执行
     */
    @Override
    public void afterCompletion(
            HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
            throws Exception {
        logger.info(request.getRequestURI()+"afterCompletion执行结束");
    }

}

2.定义一个Config类，实现WebMvcConfigurer接口

创建拦截器之后，我们还需要将其注册到Spring程序中，以便启用它。
注册拦截器
创建一个Spring配置类实现WebMvcConfigurer接口，并重写addInterceptors()方法，用于将拦截器添加到程序中

作用是控制拦截哪个controller，拦截哪个路径，放开哪个路径

/**
 * @author rick
 */
@Configuration
public class InterceptorConfig implements WebMvcConfigurer {
    @Autowired
    private EasyLogControllerInterceptor easyLogControllerInterceptor;

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        //addPathPatterns用于添加拦截路径
        //excludePathPatterns用于添加不拦截的路径
        registry.addInterceptor(easyLogControllerInterceptor)
                .addPathPatterns("/send")
                .addPathPatterns("/hello");
    }

    /**
     * 此方法用于配置静态资源路径
     */
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/**").addResourceLocations("classpath:/my/");
    }
}

3.创建一个接口用于查看拦截器的执行效果

/**
 * @author rick
 */
@RestController
public class TestController {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    @GetMapping("/hello")
    public Map<String,String> hello(){
        Map<String,String> response=new HashMap<>();
        logger.info("------hello");
        response.put("msg","hello");
        return response;
    }
    @GetMapping("/send")
    public Map<String,String> send(){
        Map<String,String> response=new HashMap<>();
        logger.info("------send");
        response.put("msg","send");
        return response;
    }
}