Validating xml against dtd in java
When you pass a URI identifying a particular schema language to that know how to process your schema language.
A single implementation usually supports only a subset of the numerous languages and models.
You can also tell whether and how a type is derived from another type.
Beyond that, understanding the type is up to your program.
However, it's usually done before any further processing of the input takes place.
(This description is painted with broad strokes -- there are exceptions.)Until recently, the exact Application Programming Interface (API) by which programs requested validation varied with the schema language and parser.