How to replace text of Paragraph in Itext? - itext

Question

I want to set page number when I merge pdf files. The page number paragraph will defind by someone to custom style what he want. Now I can add text to the paragraph(like doc.add(paragraph.add(text))), but I can not replace it.
public static byte[] mergePdf(Map<String, PdfDocument> filesToMerge, Paragraph paragraph) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfDocument pdfDoc = new PdfDocument(new PdfWriter(baos));
Document doc = new Document(pdfDoc);
pdfDoc.initializeOutlines();
PdfPageFormCopier formCopier = new PdfPageFormCopier();
int page = 1;
for (Map.Entry<String, PdfDocument> entry : filesToMerge.entrySet()) {
String title = entry.getKey();
PdfDocument srcDoc = entry.getValue();
int numberOfPages = srcDoc.getNumberOfPages();
for (int i = 1; i <= numberOfPages; i++, page++) {
Text text = new Text(String.format("page %d", page));
srcDoc.copyPagesTo(i, i, pdfDoc, formCopier);
if (i == 1) {
text.setDestination("p" + page);
PdfOutline rootOutLine = pdfDoc.getOutlines(false);
PdfOutline outline = rootOutLine.addOutline(title);
outline.addDestination(PdfDestination.makeDestination(new PdfString("p" + page)));
}
// I want do like "doc.add(paragraph.set(text))";
// paragraph already have been set position,font,fontSize and so on. SO I dont want to "new Paragraph(text)"
doc.add(paragraph.add(text));
}
}
for (PdfDocument srcDoc : filesToMerge.values()) {
srcDoc.close();
}
doc.close();
return baos.toByteArray();
}

Answer 1

I am the questioner. At last I resolve the question do like this:
public class MyParagraph extends Paragraph {
public MyParagraph() {
}
public void setContent(Text text) {
List<IElement> children = this.getChildren();
if (!children.isEmpty()) {
children.clear();
}
children.add(text);
}
}