帮我看看这个提示

[l506345z]

提示信息如下：
The serializable class RefreshServlet does not declare a static final serialVersionUID field of type long
提示在：
public class RefreshServlet extends HttpServlet的RefreshServlet这里。
问题在哪？怎么解决？请大虾们赐教
package com.test.reception;

import java.io.*;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import javax.servlet.*;
import javax.servlet.http.*;

public class RefreshServlet extends HttpServlet {

private static List availableModels = new ArrayList();

protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//处理Requset
}

protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}

public void init() throws ServletException {}

private static class MakeModelYear {
private int modelYear;
public MakeModelYear(int modelYear, String make, String model) {
this.modelYear = modelYear;
}
}
}

[tanlangxing]

没这个提示呢

[l506345z]

警告提示,问题在哪里啊?

[羽佳0627]

不用管它
警告你没有对servlet声明序列化标志，其实Java虚拟机会自动生成