Serlvet3.0新特性注解@WebServlet

package com.liu.filter;import java.io.IOException;import javax.servlet.ServletConfig;import javax.servlet.ServletException;import javax.servlet.annotation.WebInitParam;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;//注解配置@WebServlet(displayName = 'UserServlet' //描述, name = 'UserServlet', //servlet名称urlPatterns = { '/user' }, //urlloadOnStartup = 1, //启动项initParams = { @WebInitParam(name = 'username', value = '张三') })//初始化参数public class UserServlet extends HttpServlet {  private String username;  @Override public void init(ServletConfig config) throws ServletException {  //获取初始化信息：张三  username = config.getInitParameter('username'); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp)   throws ServletException, IOException {//主要内容操作 }}