在当前JSP页面中怎么修改图片,让图片在点击浏览按钮的同时更新显示的图片?[
<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-bean" prefix="bean"%>
<%@ taglib uri="http://jakarta.apache.org/struts/tags-html" prefix="html"%>
<html>
<head>
<title>JSP for UserForm form</title>
</head>
<body>
<html:form action="/user.do?method=upp" enctype="multipart/form-data" method="post">
<table border="1" align="center" width="60%">
<tr>
<td align="right">姓名:</td>
<td><html:text property="user.u_name"/></td>
</tr>
<tr>
<td align="right">性别:</td>
<td>
<html:radio property="user.u_sex" value="男" />男
<html:radio property="user.u_sex" value="女"/>女
</td>
</tr>
<tr>
<td align="right">年龄:</td>
<td><html:text property="user.u_age"/></td>
</tr>
<tr>
<td align="right">相片:</td>
<td><img alt="" src="${pageContext.request.contextPath}/${user.uppath}"/><br>
<html:file property="user.u_img"></html:file>
</td>
</tr>
<html:hidden property="user.u_id"/>
<tr>
<td colspan="10" align="center"><html:submit value="确定"/></td>
</tr>
</table>
</html:form>
</body>
</html>