How can i download file from a pageflow portlet in Webloigc Portal?

Question

How can i download file from a portlet in Webloigc Portal?
My Question is, when i download files used codes in a pageflow listed below,
it didn't work. but in non-portal environments, it worked well.
How can I download a file from a portlets in portal??
Thx in advanced.
this.getResponse().setContentType ( "application/ms-excel" ) ;
this.getResponse().setHeader ( "Content-Disposition" ,"attachment;filename="
+new String("Excel.xls".getBytes(),"iso-8859-1")) ;
sth.write(this.getResponse().getOutputStream());

Answer 1

i always use an old fashioned method when i have to do this, i create a new jsp that contains a scriptlet that writes to the ServletOutputStream.
<i>outputWriter.jsp</i>
// define your own class to get file here, otherwiser use netui-data:callControl tag
<code><pre>
File file = FileControl.getFile(fileName);
String fileName = (String) request.getParameter("fileName");
response.setContentType(file.getContentType());
ServletOutputStream sos = response.getOutputStream();
InputStream is = file.getInputStream();
for(int i = 0; (i = is.read()) != -1;)
sos.write(i);
sos.close();
</pre>
</code>
i then call this jsp from the jsp to which i forward in my action using a simple url rewrite with file name on the url.
<a href=outputWriter.jsp?fileName=nameOfFileToDownload