https://www.datalogics.com/access-xfa-forms-with-forms-flattener
How to access XFA forms
PDF Forms Flattener is a command-line application that automates batch processing and flattening of static XFA, dynamic XFA and AcroForms for easier printing,...
how to accessxfa forms
https://helpx.adobe.com/hk_en/acrobat/desktop/troubleshoot/pdf-viewing-editing-issues/cannot-edit-xfa-forms.html
Unable to edit XFA forms
Learn workarounds to modify XFA forms in Adobe Acrobat Pro, including saving as PostScript or printing to PDF.
xfa formsunableedit
https://blog.idrsolutions.com/tag/xfa-forms/
XFA forms Archives - Java PDF Blog
xfa formsarchivesjavapdfblog
https://api.itextpdf.com/iText/java/7.0.7/com/itextpdf/forms/xfa/package-tree.html
com.itextpdf.forms.xfa Class Hierarchy (iText 7 7.0.7 API)
class hierarchyitextpdfformsapi