Fillable PDF save/upload after update

I need help to determine if this use case is possible. I have a fillable pdf which is viewable through the browser pdf-plugin. After the user enters data into the fillable pdf form, I would like to upload and save it. Creating the stream source and sending to the client side view is easy. How would one approach saving the front-end updates and forward it back to the back-end?

TIA

InputStream is = new ByteArrayInputStream(report.getPdfForm());
					StreamResource resource = new StreamResource(report.getName(), () -> is);
					resource.setContentType("application/pdf");
					resource.setCacheTime(0);