There doesn't seem to be an easy way to validate an XML document against a schema, so I figured I would roll my own library for it. Now, with that library, validating against a schema all of a sudden becomes easy. In the past, I hardly ever considered validating a document against a schema in my tests, but now I find myself doing it all over the place.
Anyway, I will just give a brief introduction. (And there really isn't that much to talk about.)
First of all, let's assume that you have a File reference to an XML file (xml) and a File reference to a RelaxNG schema file (schema). Now, in order to validate that file from JUnit, all you have to do is this:
Expected: conforming to sample.rng
but: tag name "foo" is not allowed. Possible tag names are: <bar> at line <2>