Disable DTD validations in XML transform using a StreamSource

Is there a way to disable DTD validations in an XML transformation using a StreamSource ?

The code here

String source = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><!-- COMMENT --><!DOCTYPE config SYSTEM \"validation.dtd\" ><config><host>localhost</host><port>2000</port><buffer-size>32768</buffer-size><retry-count>0</retry-count><retry-timeout>5000</retry-timeout><connect-timeout>60000</connect-timeout><write-timeout>5000</write-timeout></config>";
ByteArrayInputStream sourceInputStream = new ByteArrayInputStream(source.getBytes());

TransformerFactory optimusPrimeFactory = TransformerFactory.newInstance(
        "com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl", Test.class.getClassLoader());

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(sourceInputStream));

Result result = new StreamResult(new StringWriter());
Transformer bumblebee = optimusPrimeFactory.newTransformer();

bumblebee.transform(new StreamSource(bufferedReader), result);

for transforming this XML piece

<?xml version="1.0" encoding="UTF-8"?>
<!-- COMMENT -->
<!DOCTYPE config SYSTEM "validation.dtd" >
<config>
    <host>localhost</host>
    <port>2000</port>
    <buffer-size>32768</buffer-size>
    <retry-count>0</retry-count>
    <retry-timeout>5000</retry-timeout>
    <connect-timeout>60000</connect-timeout>
    <write-timeout>5000</write-timeout>
</config>

will always throw for a FileNotFoundException since the DTD file does not exist, but I want to ignore the DTD validations and references in the transformation process.

This page proposes a solution with a custom EntityResolver, but I don't want to use SAX because it does not work in a streaming way.

I've tried setting features on the factory, but I can't seem to find the right ones:

optimusPrimeFactory.setFeature("http://ift.tt/1gFjbcP", false);
optimusPrimeFactory.setFeature("http://ift.tt/Qb9Hvl", false);

Please note that the use of the XSLTC TrasformerFactory implementation cannot be changed.