docx4j: docx到pdf的转换- docx内容不会逐页显示为pdf

WordprocessingMLPackage wordMLPackage = WordprocessingMLPackage.load(new File("input.docx"));

FOSettings foSettings = Docx4J.createFOSettings();
foSettings.setApacheFopMime("application/pdf");

ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
Docx4J.toFO(foSettings, outputStream, Docx4J.FLAG_EXPORT_PREFER_XSL);

FopFactory fopFactory = FopFactory.newInstance(new File(".").toURI());
FOUserAgent foUserAgent = fopFactory.newFOUserAgent();
OutputStream pdfOutputStream = new FileOutputStream(new File("output.pdf"));

Fop fop = fopFactory.newFop(MimeConstants.MIME_PDF, foUserAgent, pdfOutputStream);
TransformerFactory transformerFactory = TransformerFactory.newInstance();
Transformer transformer = transformerFactory.newTransformer();

Source source = new StreamSource(new ByteArrayInputStream(outputStream.toByteArray()));
Result result = new SAXResult(fop.getDefaultHandler());

transformer.transform(source, result);