[jdom-interest] error referencing xml schema from xml file

[Makhlin, Boris]

Hi,
When I parse following xml with turned on validation, I am getting error
Error on line 2 of document file:/D:/resin-1.2.3/doc/purchaseOrder.xml:
General Schema Error: Grammar with uri :
http://localhost:8080/purchaseOrder, can not found.

<?xml version="1.0"?>
<apo:purchaseOrder xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:apo="http://localhost:8080/purchaseOrder" orderDate="1999-10-20">
</apo:purchaseOrder>

I am using Resin http server.
I can copy and paste http://localhost:8080/purchaseOrder.xsd to my brower
address field to load purchaseOrder.xsd into it. I don't see text or tree in
the browser just a white screen but when I view source I see xsd content.
This means JDOM should have access to xml schema, but it doesn't. I tried to
debug xerces XMLValidator because that is where exception is comming from.
But my source, which I just downloaded doesn't have definition of
validateElementAndAttributes method therefore it I can not compile it.

Does my xml looks right? 
I am missing something very simple. Please, help me resolve my problem. Any
ideas are appreciated.

thank you