SpringBoot(10) Servlet3.0的注解：自定义原生Servlet、自定义原生Listener

一、自定义原生Servlet

1、启动类里面增加注解 @ServletComponentScan

2、Servlet上添加注解  @WebServlet(name = "userServlet",urlPatterns = "/v1/api/test/customs")

 @WebServlet(name = "userServlet",urlPatterns = "/v1/api/test/customs")
 public class UserServlet extends HttpServlet{

      @Override
      public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

          resp.getWriter().print("custom sevlet");
          resp.getWriter().flush();
          resp.getWriter().close();
      }

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

 }

二、自定义原生Listener

常用的监听器 servletContextListener、httpSessionListener、servletRequestListener

servletContextListener：服务启动，一般用于初始化加载

servletRequestListener：访问启动，一般用于统计

 @WebListener
 public class CustomContextListner implements ServletContextListener{

     @Override
     public void contextInitialized(ServletContextEvent sce) {
         System.out.println("======contextInitialized========");
         //启动时触发
     }

     @Override
     public void contextDestroyed(ServletContextEvent sce) {
         System.out.println("======contextDestroyed========");

     }

 }

 @WebListener
 public class RequestListener implements ServletRequestListener {

     @Override
     public void requestDestroyed(ServletRequestEvent sre) {
         // TODO Auto-generated method stub
         System.out.println("======requestDestroyed========");
     }

     @Override
     public void requestInitialized(ServletRequestEvent sre) {
         System.out.println("======requestInitialized========");

     }

 }