Java EE (Java Enterprise Edition) General Discussion

Why does this simple code throw javax.xml.parsers.FactoryConfigurationError with the message "Provider org.apache.xerces.jaxp.SAXParserFactoryImpl not found" in Java 5? I think the answer is that it should be looking for the renamed class com.sun.org.apache.xerces.jaxp.SAXParserFactoryImpl. But why doesn't it do that by default?

import javax.xml.parsers.*;

public class SAXValidate {

public static void main(String[] args) throws Exception {
SAXParserFactory factory = SAXParserFactory.newInstance();
SAXParser parser = factory.newSAXParser();
}
}