> My question is, is there a way to either not have the file get written
> in the first place, or is there a way to force a delete of that file?

You could do something akin to this (untested) code:

File xml = new File("C:/temp.xml");
File xsl = new File("C:/temp.xsl");

Source xmlStreamSource = new StreamSource(xml.toURI().toString());
Source xslStreamSource = new StreamSource(xsl.toURI().toString());

TransformerFactory factory = TransformerFactory.newInstance();
Transformer transformer = factory.newTransformer(xslStreamSource);

ByteArrayOutputStream bos = new ByteArrayOutputStream();
StreamResult result = new StreamResult(bos);
try {
      transformer.transform(xmlStreamSource, result);
      // Write the result (ie, the byte array) to File
}
catch(TransformerException e) {
      // Do something else...
}

--PETE