问如何填写现有PDF的表单，然后使用itext将其添加到新PDF

EN

PdfReader reader = new PdfReader(src);
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(dest));
AcroFields form = stamper.getAcroFields();
form.setField("name", "John");
stamper.setFormFlattening(true);
stamper.close();
reader.close();
Document document = new Document();
PdfWriter writer = PdfWriter.getInstance(document, new FileOutputStream(dest2));
document.open();
PdfContentByte cb = writer.getDirectContent();
//Loading the filled form again as a file
PdfReader reader2 = new PdfReader(dest);
PdfImportedPage page = writer.getImportedPage(reader2, 1);
document.newPage();
cb.addTemplate(page, 0, 0);
document.newPage();
document.add(new Paragraph("my timestamp"));
document.close();