Do you use <uri .../> entries to declare this in catalog?

In this case, no I do not use uri as I'm using a urn:publicid:...

This is really a follow-on bug to 40338:

   http://www.netbeans.org/issues/show_bug.cgi?id=40338

Here's an example.

This document/schema/catalog combination works through Xerces 2.6.2:

The schema:
<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
           
targetNamespace="urn:publicid:IDN+cde.berkeley.edu:milowski:schemas:example-form:event:200402"
           
xmlns="urn:publicid:IDN+cde.berkeley.edu:milowski:schemas:example-form:event:200402">

<xsd:element name="event">
<xsd:complexType>
<xsd:sequence>
<xsd:element name="title" form='qualified' type="xsd:string"/>
<xsd:element name="location" form='qualified' type="xsd:string"/>
<xsd:element name="presenter" form='qualified' type="xsd:string"/>
<xsd:element name="description" form='qualified'>
<xsd:complexType>
<xsd:sequence>
<xsd:element name="p" form='qualified' type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
</xsd:element>
</xsd:sequence>
<xsd:attribute name="start-date" type="xsd:string" use="required"/>
</xsd:complexType>
</xsd:element>

</xsd:schema>

The catalog:
<catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"
prefer='public'>                

    <uri
name="http://cde.berkeley.edu/~milowski/schemas/example-form/event/200402"
uri="event.xsd"/>

    <public publicId="IDN
cde.berkeley.edu//milowski//schemas//example-form//event//200402"
uri="event.xsd"/>

</catalog>

The instance:

<?xml version="1.0" encoding="UTF-8"?>

<event
xmlns="urn:publicid:IDN+cde.berkeley.edu:milowski:schemas:example-form:event:200402"
start-date="4/16/2004" >
<title>Practical RDF</title>
<location>Room 202, South Hall</location>
<presenter>Norm Walsh</presenter>
<description><p>Norm Walsh is coming to talk about pratical
RDF.</p></description>
</event>

Petr P, you can take the implementation directly from Xerces (probably
default EntityResolver impl). I hope it's not Xerces specifics
document/schema/catalog combination handling and that a specification
exists.

Alex provided link to spec <http://www.faqs.org/rfcs/rfc3151.html>.

It could also address current problems with validating deploment
descriptors described using XML Schema.

In the issue 45212 are the instructions how to add scheams to XML catalog.

*** This issue has been marked as a duplicate of 45212 ***

I don't think it is a dup.
Please resolve this issue again without marking this bug as duplicate
of mentioned issue. That issue is hotchpotch of everything.
Thanks

For XML validation against XML schema, the systemId should be mapped
to a uri string pointing to the location. The XML Oasis Catalog
template describes how to do that. 

Created attachment 17406 [details]
OASIS Catalog

Created attachment 17407 [details]
Sample Document that should validate

Created attachment 17408 [details]
XML Schema for event.xml

Created attachment 17409 [details]
Sample Driver for Xerces

This schema is not resolved via a system identifier.  It uses a
'public' element in the catalog to resolve the URN of the XML
namespace for the schema.  This does not work inside Netbeans but it
does work outside via Xerces.

If you mount the catalog, it properly shows the mapping of the public
identifier but the validate button on a conforming document says that
it can't find the declaration of the root element.

I have attached sample files and a sample driver for Xerces.

Thank you very much for the example.
Now I understand what's the problem.
We use the own implementation of entity catalog - that's the problem.
We should switch to the standard Apache resolver-1.1 version (as used
in the example).
This issue is very similar to the issue 48029 and both depend on the
issue 27930.
However I can trach this as a standalone issue.

Fixed.

The diffs are referenced in issue 48029.
Thank you Alex for your assistance.