how to check an xml document for namespaces normality or confusion using the standard java DOM API

assume that:

1. An XML document is deceptive if it maps the same namespace prefix to two different namespace URIs at different points.


2. A document is confusing if it maps two different namespace prefixes to the same namespace URI in different scopes.


3. A document is super-confusing if it maps two different namespace prefixes to the same URI in the same scope.


4. A document is ok if it is neither deceptive nor confusing.


5. A document is normal (or in namespace-normal form) if all namespace declarations appear on the root element and it is not super-confusing.

how to check the document namespaces using the standard java dom api?

someone help me...