1、使用Servlet API

@ServletComponentScan(basePackages = “com.atguigu.admin”)
:指定原生Servlet组件都放在那里
@WebServlet(urlPatterns ="/my")：效果：直接响应，没有经过Spring的拦截器？
@WebFilter(urlPatterns={"/css/","/images/"})
@WebListener

@ServletComponentScan(basePackages = "com.atguigu.admin")
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)public class Boot05WebAdminApplication {public static void main(String[] args) {SpringApplication.run(Boot05WebAdminApplication.class, args);}}

@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {resp.getWriter().write("66666");}
}

@Slf4j
@WebFilter(urlPatterns = {"/css/*","/images/*"})
public class MyFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {log.info("init finished");}@Overridepublic void destroy() {log.info("destroy finished");}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {log.info("myFilter work");filterChain.doFilter(servletRequest,servletResponse);}
}

@Slf4j
@WebListener
public class MyServletContextListener implements ServletContextListener {@Overridepublic void contextInitialized(ServletContextEvent sce) {log.info("MyServletContextListener init finished");}@Overridepublic void contextDestroyed(ServletContextEvent sce) {log.info("MyServletContextListener destory finished");}}

2、使用RegistrationBean

@Slf4j
//@WebFilter(urlPatterns = {"/css/*","/images/*"})
public class MyFilter implements Filter {@Overridepublic void init(FilterConfig filterConfig) throws ServletException {log.info("init finished");}@Overridepublic void destroy() {log.info("destroy finished");}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {log.info("myFilter work");filterChain.doFilter(servletRequest,servletResponse);}
}//=======================================================//@WebServlet(urlPatterns = "/my")
public class MyServlet extends HttpServlet {@Overrideprotected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {resp.getWriter().write("66666");}}//=================================================================@Slf4j
//@WebListener
public class MyServletContextListener implements ServletContextListener {@Overridepublic void contextInitialized(ServletContextEvent sce) {log.info("MyServletContextListener init finished");}@Overridepublic void contextDestroyed(ServletContextEvent sce) {log.info("MyServletContextListener destory finished");}}

@Configuration(proxyBeanMethods = true)
public class MyRegistConfig {@Beanpublic ServletRegistrationBean myServlet(){MyServlet myServlet = new MyServlet();return new ServletRegistrationBean(myServlet,"/my","/my02");}@Beanpublic FilterRegistrationBean myFilter(){MyFilter myFilter = new MyFilter();//      方式一:
//        return new FilterRegistrationBean(myFilter,myServlet());//方式二:FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(myFilter);filterRegistrationBean.setUrlPatterns(Arrays.asList("/my","/css/*"));return filterRegistrationBean;}@Beanpublic ServletListenerRegistrationBean myListener(){MyServletContextListener myServletContextListener = new MyServletContextListener();return new ServletListenerRegistrationBean(myServletContextListener);}}

注意:

@Configuration(proxyBeanMethods = true)

保证依赖的组件始终是单实例的

如果我们写成

@Configuration(proxyBeanMethods = false)

说明我们当前类，每次调用一次myServlet方法，就会创建一个新的MyServlet，有可能导致我们一调用下面的过滤器方法就会创建一个新的MyServlet，会导致我们容器中有很多冗余的其他对象！

return new FilterRegistrationBean(myFilter,myServlet());