Document document = new Document(dataDir + "Sample1.one");

UserSavingCallbacks savingCallbacks = new UserSavingCallbacks();
savingCallbacks.setRootFolder("documentFolder");
savingCallbacks.setCssFolder("css");
savingCallbacks.setKeepCssStreamOpened(true);
savingCallbacks.setImagesFolder("images");
savingCallbacks.setFontsFolder("fonts");

HtmlSaveOptions options = new HtmlSaveOptions();
options.setFontFaceTypes(FontFaceType.Ttf);
options.setCssSavingCallback(savingCallbacks);
options.setImageSavingCallback(savingCallbacks);
options.setFontSavingCallback(savingCallbacks);
options.setExportCss(ResourceExportType.ExportEmbedded);
options.setExportImages(ResourceExportType.ExportEmbedded);
options.setExportFonts(ResourceExportType.ExportEmbedded);

File dir = new File(savingCallbacks.getRootFolder());
if (!dir.exists()) {
	dir.mkdir();
}

document.save(Paths.get(savingCallbacks.getRootFolder(), "document.html").toString(), options);

try (OutputStreamWriter writer = new OutputStreamWriter(savingCallbacks.getCssStream(), "utf-8")) {
	writer.write(System.lineSeparator());
	writer.write("/* This line is appended to stream manually by user */");
	writer.close();
}