Getting "net.sf.saxon.trans.XPathException: java.io.IOException: Stream Closed" exception in my java code during xslt transformation

I am using xslt along with java to process and convert input xml files to produce multiple result documents.
But I am getting below error at transformer.transform(input, output) in my java transformation class.

Please help me in this.

Stack Trace:

java.io.IOException: Stream Closed
net.sf.saxon.trans.XPathException: java.io.IOException: Stream Closed
	at net.sf.saxon.event.XMLEmitter.close(XMLEmitter.java:264)
	at net.sf.saxon.event.ProxyReceiver.close(ProxyReceiver.java:90)
	at net.sf.saxon.event.UncommittedSerializer.close(UncommittedSerializer.java:53)
	at net.sf.saxon.event.ImplicitResultChecker.close(ImplicitResultChecker.java:92)
	at net.sf.saxon.event.ProxyReceiver.close(ProxyReceiver.java:90)
	at net.sf.saxon.event.ComplexContentOutputter.close(ComplexContentOutputter.java:507)
	at net.sf.saxon.Controller.transformDocument(Controller.java:1848)
	at net.sf.saxon.Controller.transform(Controller.java:1621)

Java code snippet:

String outputDirectory = fileParentLocation + "\\resultFolder\\";
FileTools.createDirectory(new File(outputDirectory));

try {
TransformerFactory factory =
		TransformerFactory.newInstance("net.sf.saxon.TransformerFactoryImpl", getClass().getClassLoader());

InputStream xsltResourceAsStream =
		getClass().getClassLoader().getResourceAsStream("ConvertInputXmlFiles.xslt");
Source xslt = new StreamSource(xsltResourceAsStream);
Result output = new StreamResult(new File(outputDirectory + "test.xml"));
		
Transformer transformer = factory.newTransformer(xslt);
transformer.setParameter("versionName", versionName);        

  if (filesToBeTransformed != null && !filesToBeTransformed.isEmpty()) {
	for (File file : filesToBeTransformed) {
		Source input = new StreamSource(file);
		transformer.transform(input, output);
	}
  }
}

Thanks in advance !!

You're trying to append multiple transformation results to the same output stream, and that doesn't work.

I think it would probably work if you created a FileOutputStream and supplied that in the StreamResult, instead of supplying the File. Basically, whoever creates a stream is responsible for closing it, and if you supply a File, then Saxon creates the stream, and will close it at the end of the transformation, but if you create the stream, then you can choose whether to close it or not.

Your prose question says you're trying to produce multiple output documents, but your code seems to be trying to produce a single result document. Which is it?

Note also, with Saxon we recommend doing TransformerFactory.newTemplates() once to compile the stylesheet, and then creating a new Transformer for each transformation using Templates.newTransformer(). Serial reuse of a single Transformer is allowed, but may cause unnecessary accumulation of resources in internal caches.