struts+hibernate图片存储问题！

我想把图片存到一个文件夹下面，数据库只记录图片路径，代码如下：

linkAction.java
public ActionForward unspecified(ActionMapping mapping, ActionForm form,
HttpServletRequest request, HttpServletResponse response) {
LinkForm Link = (LinkForm) form;
// 添加链接
Link link = new Link();
link.setUrl(Link.getUrl());
link.setTitle(Link.getTitle());
FormFile thefile = Link.getPicture();//把上传的文件读取到控制器中
String filename = thefile.getFileName();//读取文件名
link.setPicture(filename);
boolean b = LinkDAO.addLink(link);
String dir = servlet.getServletContext().getRealPath("/include/link/");
//取得当前servlet的全路径
try
{ //执行保存文件操作
InputStream stream = thefile.getInputStream();//获取文件流