Re:Validating against a Schema

[Richard Featherstone <R.Featherstone@uea.ac.uk>]

Could someone either tell me how or point me in the right direction to
find out how to validate an XML doc against a Schema using Java.  I can
parse without validating but don't know 

a) how the parser can decide what Schema is being used from the XML doc
and where to locate it

b) how to configure the parser to validate the doc against the schema

I apologise if this is the wrong place to ask a question like this but
I've spent days looking everywhere for the answer.

thanks in advance

Richard