我用eclipse新建一个动态网站工程，主类名是HelloWorld,但在类名上老报错：
The serializable class HelloWorld does not declare a static final
serialVersionUID field of type long
运行时tomcat报错：type Status report

message /test/HelloWorld

description The requested resource (/test/HelloWorld) is not available.


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怎么回事啊，谁能告诉我啊，谢谢！！！1[em10]

源码是：
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Servlet implementation class for Servlet: HelloWorld
*
*/
public class HelloWorld extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
    /* (non-Java-doc)
     * @see javax.servlet.http.HttpServlet#HttpServlet()
     */
    public HelloWorld() {
        super();
    }       
    
    /* (non-Java-doc)
     * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }      
    
    /* (non-Java-doc)
     * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }                 
}