由于SpringBoot默认是以jar包的方式启动嵌入式的Servlet容器来启动SpringBoot的web应用，没有web.xml文件。 注册三大组件用以下方式 ServletRegistrationBean ```java //注册三大组件 @Bean public ServletRegistrationBean myServlet(){ ServletRegistrationBean registrationBean = new ServletRegistrationBean(new MyServlet(),"/myServlet"); return registrationBean; } ``` FilterRegistrationBean ```java @Bean public FilterRegistrationBean myFilter(){ FilterRegistrationBean registrationBean = new FilterRegistrationBean(); registrationBean.setFilter(new MyFilter()); registrationBean.setUrlPatterns(Arrays.asList("/hello","/myServlet")); return registrationBean; } ``` ServletListenerRegistrationBean ```java @Bean public ServletListenerRegistrationBean myListener(){ ServletListenerRegistrationBean<MyListener> registrationBean = new ServletListenerRegistrationBean<>(new MyListener()); return registrationBean; } ``` SpringBoot帮我们自动SpringMVC的时候，自动的注册SpringMVC的前端控制器；DIspatcherServlet； DispatcherServletAutoConfiguration中： ```java @Bean(name = DEFAULT_DISPATCHER_SERVLET_REGISTRATION_BEAN_NAME) @ConditionalOnBean(value = DispatcherServlet.class, name = DEFAULT_DISPATCHER_SERVLET_BEAN_NAME) public ServletRegistrationBean dispatcherServletRegistration( DispatcherServlet dispatcherServlet) { ServletRegistrationBean registration = new ServletRegistrationBean( dispatcherServlet, this.serverProperties.getServletMapping()); //默认拦截： / 所有请求；包静态资源，但是不拦截jsp请求； /*会拦截jsp //可以通过server.servletPath来修改SpringMVC前端控制器默认拦截的请求路径 registration.setName(DEFAULT_DISPATCHER_SERVLET_BEAN_NAME); registration.setLoadOnStartup( this.webMvcProperties.getServlet().getLoadOnStartup()); if (this.multipartConfig != null) { registration.setMultipartConfig(this.multipartConfig); } return registration; } ``` 2）、SpringBoot能不能支持其他的Servlet容器；