Parse XML Schema with Castor

[Anna]

Hi all.
I want to parse an XML schema and retrieve its structure.
I found castor package and I think that's what I need, but I can't
find few things.

I have an org.exolab.castor.xml.schema.Schema object, and I need to
get the following information:
names of all elements defined in the schema - getElementDecls()
returns only top-level elems.
for each element, get elements and attributes that are allowed under
this element.
for each element, get elements that can be a parent of this element.
etc.

Can I get all this information using castor xml.schema package?
If yes (which I'm almost sure of), can somebody give me some hints on
how to do it?
I couln't find any examples available.

Thank you very much for help.

Anna