我想用struts2做文件上传， 在action中的username,password,file，fileFileName，fileContentType的值为空，我写了get set方法的，不是说struts2会自动注入，这是怎么回事了，谢谢
jsp代码：
<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib prefix="s" uri="/struts-tags" %>
<html>
<head>
<title>fileupload</title>
</head>
<body>
<!-- 用fileUpload上传文件一form定要加 enctype="multipart/form-data"-->
<s:form action="upload" theme="simple" enctype="multipart/form-data">
<table align="center" width="40%" border="1">
<tr>
<td>
username
</td>
<td>
<s:textfield name="username" />
</td>
</tr>
<tr>
<td>
password
</td>
<td>
<s:textfield name="password" />
</td>
</tr>
<tr>
<td>
file
</td>
<td>
<s:file name="file"/>
</td>
</tr>
<tr>
<td>
<s:submit value="submit"/>
</td>
<td>
org.apache.jasper.JasperException: Unable to compile class for JSP:
An error occurred at line: 52 in the jsp file: /vip_info.jsp
ÕË cannot be resolved
49: <table border="1& ......
