Java代码注册servlet

package com.czy.listeners;

import javax.servlet.Servlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;
import javax.servlet.annotation.WebListener;

import com.czy.servlet.MessageServlet;

/**
*  服务器启动和关闭时的监听器
* @author czy
*
*/
@WebListener
  public class MyContextListener implements ServletContextListener {


   public void contextInitialized(ServletContextEvent sce)  { 
        System.out.println("服务器正在启动");
        ServletContext context = sce.getServletContext();
        try {
           Servlet servlet = context.createServlet(MessageServlet.class);
           ServletRegistration.Dynamic reg = context.addServlet("MessageServlet", servlet);
           reg.addMapping("/goodbye.do");
       } catch (ServletException e) {
           e.printStackTrace();
       }
   }

   public void contextDestroyed(ServletContextEvent sce)  { 
       System.out.println("服务器正在关闭");
  }
}