实例

创建MyInterceptor

public class MyInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("preHandle");
        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        System.out.println("postHandle");

    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        System.out.println("afterCompletion");

    }
}

创建WebMvcConfig

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(myInterceptor()).addPathPatterns("/**");
    }
    @Bean
    MyInterceptor myInterceptor(){
        return new MyInterceptor();
    }
}

创建HelloController

@RestController
public class HelloController {

    @GetMapping("/hello")
    public String hello(){
        return "hello";
    }
}

启动之后，控制台输出

preHandle
postHandle
afterCompletion