1. A method of resolving Extensible Markup Language (XML) schema files comprising: receiving an XML instance document that includes data to be validated using an XML schema file at an XML validating system; parsing the XML instance document to map an external XML schema reference to the XML schema file defined by a source outside the XML validating system to an internal XML schema reference defined internal to the XML validating system; and resolving the internal XML schema reference using a Java Classloader to provide the XML schema file as an input stream to the XML validating system.