使用IText7创建二维码的示例

import com.itextpdf.barcodes.BarcodeQRCode;
import com.itextpdf.kernel.colors.ColorConstants;
import com.itextpdf.kernel.geom.PageSize;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.element.Image;

PdfDocument pdf = new PdfDocument(new PdfWriter("output.pdf"));
Document document = new Document(pdf, PageSize.A4);

BarcodeQRCode qrCode = new BarcodeQRCode("https://www.example.com", null);

Image qrCodeImage = new Image(qrCode.createFormXObject(ColorConstants.BLACK, pdf));

document.add(qrCodeImage);

document.add(new Paragraph("扫描二维码以访问网站"));

document.close();