@WebServlet(name = "IndexServlet",urlPatterns = "/hello")
  public class IndexServlet extends HttpServlet {
    @Override
    public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
      resp.getWriter().print("hello word");
      resp.getWriter().flush();
      resp.getWriter().close();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
      this.doGet(req, resp);
    }
  }

 @WebListener
  public class IndexListener implements ServletContextListener {
    private Log log = LogFactory.getLog(IndexListener.class);

    @Override
    public void contextInitialized(ServletContextEvent servletContextEvent) {
      log.info("IndexListener contextInitialized");
    }

    @Override
    public void contextDestroyed(ServletContextEvent servletContextEvent) {

    }
  }

@WebFilter(urlPatterns = "/*", filterName = "indexFilter")
  public class IndexFilter implements Filter {
    Log log = LogFactory.getLog(IndexFilter.class);

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
      log.info("init IndexFilter");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
      log.info("doFilter IndexFilter");
      filterChain.doFilter(servletRequest,servletResponse);

    }

    @Override
    public void destroy() {

    }
  }

@Target(ElementType.TYPE)
  @Retention(RetentionPolicy.RUNTIME)
  @Documented
  @Import(ServletComponentScanRegistrar.class)
  public @interface ServletComponentScan {


    @AliasFor("basePackages")
    String[] value() default {};


    @AliasFor("value")
    String[] basePackages() default {};


    Class<?>[] basePackageClasses() default {};

  }

  @SpringBootApplication
  @ServletComponentScan
  public class AppApplication {

    public static void main(String[] args) throws Exception {
      SpringApplication.run(AppApplication.class, args);
    }

  }

  @Bean
  public ServletRegistrationBean indexServletRegistration() {
    ServletRegistrationBean registration = new ServletRegistrationBean(new IndexServlet());
    registration.addUrlMappings("/hello");
    return registration;
  }

  @Bean
  public FilterRegistrationBean indexFilterRegistration() {
    FilterRegistrationBean registration = new FilterRegistrationBean(new IndexFilter());
    registration.addUrlPatterns("/");
    return registration;
  }
  @Bean
  public ServletListenerRegistrationBean servletListenerRegistrationBean(){
    ServletListenerRegistrationBean servletListenerRegistrationBean = new ServletListenerRegistrationBean();
    servletListenerRegistrationBean.setListener(new IndexListener());
    return servletListenerRegistrationBean;
  }

@Bean
  public ServletRegistrationBean dispatcherRegistration(DispatcherServlet dispatcherServlet) {
    ServletRegistrationBean registration = new ServletRegistrationBean(dispatcherServlet);
    registration.addUrlMappings("*.do");
    registration.addUrlMappings("*.json");
    return registration;
  }