using input streams? Used with <x:transform>?

[spliffmonkey]

I am really confused. Basically I have a function. It returns and
inputstream. I am writing a jsp page that uses this inputstream. I have
tried things like:
<%
out.println(file.getStream());
%>

But the stream doesnt seem to work that way.

What I really want to do is use it with <x:tranform> tag from the
jakarta standard taglibs.
Ive succesfully used:

<c:set var="string"><%=file.getString()%></c:set>

Which clearly just gets a string. But I want to use a stream like this:

<c:set var="stream"><%=file.getStream()%></c:set>

But that doesnt seem to work.

To be honest I have no idea how to use streams. If you could point me
to some basic info on them that would be great.

Btw: I can also have it return a stream of type Reader if that is any
use. I dont really get the difference.

Thanks
T