input reader closed after IndexWriter.addDocument(doc)

[Beady Geraghty <be...@gmail.com>]

 am new to Lucene. I don't seem to be able to find the answer to my question
from the archive. I hope to get some help with my problem.
 I have :
 Document doc = new Document();
 doc.add( Field.Text( "contents", rdr );
 myIndexWriter.addDocument( doc );
 After this point, it appears that rdr is closed.
 What happens is that I want to subsequently 
use the rdr again by positioning back to the beginning
of the file, and since I opened the rdr (input stream),
I wasn't expect addDocument to close it.
 I am wondering if there is a reason that rdr should be
closed after addDocument, and if there is a way to leave it open ?
 Thank you.