jsf结合文件下载servlet

Question

我有两个（独立的）Projetcs：

1.。）包含许多链接的JSF-WebApplication

<h:outputLink value="#{file.servletLinkWithParameters}">
     <h:outputText value="#{file.caption}"/>
</h:outputLink>

2.。）Filedownload-Servlet，通过附件返回我的文件：

protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
....

response.setContentType("application/force-download");
response.setContentLength(realFilesize);
response.setHeader("Content-disposition", "attachment; filename="
                + realFilename);
final OutputStream out = response.getOutputStream();

URL url = new URL(realFilepath);
InputStream in = url.openStream();
final byte[] buffer = new byte[4096];
int length;
while ((length = in.read(buffer)) != -1) {
    out.write(buffer, 0, length);
}
in.close();
out.flush();
out.close();
}

当我尝试点击outputLink（例如url：8080 / FileDownloadHandler / download？id = R0RcGAAD）时，它会给我＆＃34; Unknown Adress＆＃34;。

但是当我在新窗口或标签中打开相同的链接时，它可以正常工作。

我不知道为什么......