<div id="login">
<h2>用户登录</h2>
<form method="post" enctype="multipart/form-data" action="http://localhost:3000/site/upload/20008">
用户名:<input id="contact" type="file" /><br/>
<input type="submit" class="btn_login" value="登录" />
</form>
</div>
console.log(req.files);