JavaWeb学习-Servlet系列-5-继承HttpServlet类-怎么解决啊？

package servletdemo01;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletDemo01 extends HttpServlet{
    
    
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----doGet--------");
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        System.out.println("-----doPost--------");
    }
    
}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://JAVA.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>ServletDemo01</display-name>
  <servlet>
          <servlet-name>ServletDemo01</servlet-name>
          <servlet-calss>servletdemo01.ServletDemo01</servlet-calss>
  </servlet>
  <servlet-mapping>
          <servlet-name>ServletDemo01</servlet-name>
          <url-pattern>/demo</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
</web-app>

怎么解决啊？

访问路劲不对啊，好得写个html页面啊

访问路径应该是访问Servlet的，你这个路径是web.xml文件的路径。按你配置文件里的配置，访问路径应该写：
http://localhost:8080/ServletDemo01/demo
ServletDemo01是你的项目名，也叫项目的虚拟路径，demo是Servlet文件的虚拟路径，就是web.xml文件里url-pattern标签里的数据。