javax.servlet.ServletException: Class packageservlet.LoginServlet is not a S
javax.servlet.ServletException: Class packageservlet.LoginServlet is not a Sservlet


报这个错是什么问题啊，我是按李兴华老师的原代码打上去的，但还是这样

package packageservlet;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import dbcon.factory.DAOFactory;
import dbcon.vo.User;
public class LoginServlet {
public void doGet(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{
String path="login.jsp" ;
String userid=req.getParameter("userid");
String userpass=req.getParameter("upassword");
List<String>info=new ArrayList<String>();
if(userid==null){
info.add("用户id不能为空!");
}
if(userpass==null){
info.add("密码不能为空!");
}
if(info.size()==0){
User user=new User();
user.setUserid(userid);
user.setPassword(userpass);
try{
if(DAOFactory.getIUserDAOInstance().findLogin(user)){
info.add("用户登录成功，欢迎"+user.getName()+"光临！");
}
else{
info.add("用户登录失败，错误的用户名和密码！");
}
}catch(Exception e){
e.printStackTrace();
}
}
req.setAttribute("info", info);
req.getRequestDispatcher(path).forward(req,resp);
}
public void doPost(HttpServletRequest req,HttpServletResponse resp)throws ServletException,IOException{
this.doGet(req, resp);
}
}


配置web.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <welcome-file-list>
  <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
<servlet-name>login</servlet-name>
<servlet-class>packageservlet.LoginServlet</servlet-class>
  </servlet>
  <servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/loginservlet</url-pattern>
  </servlet-mapping>
</web-app>
后来我加了个import javax.servlet.Servlet;（其实我也不知道为什么要这样加，只是看网上有人这样说）
就报错如下HTTP Status 404 - Servlet login is not available


------解决方案--------------------
LoginServlet要extends HttpServlet 
试下看看
------解决方案--------------------
LoginServlet 
要继承httpServlet,打少了