DomUtils is like a garbage can of static methods. It would be much easier to write code such as this:

XMLDocument doc = new XMLDocument(new File("input.xml");
XMLSchema schema = new XMLSchema("x.xsd", new ClasspathResolver());
schema.validate(doc);
doc.transform(new XSLTTransformation("y.xslt"));

or even like this:

XMLSchema schema = new XMLSchema("x.xsd", new ClasspathResolver());

XMLDocument doc = new XMLDocument("input.xml").process(schema).process(new XSLTTransformer("y.xslt"));

Using static imports of XMLDocument.xmldocument(), XSLTTransofmration.transformation(), XMLSchema.schema()

XMLDocument doc = xmldocument("input.xml").process(schema("x.xsd").process(transformation("y.xslt");

Then, going even further, with shorthands for process(schema()) and process(transformation())

XMLDocument doc = xmldocument("input.xml").validate("x.xsd").transform("y.xslt");