如何为PdfWidgetAnnotation设置字体名称和字体大小？- iText 7.1.0 for Java

import com.itextpdf.kernel.font.PdfFont;
import com.itextpdf.kernel.font.PdfFontFactory;
import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.kernel.pdf.annot.PdfWidgetAnnotation;
import com.itextpdf.kernel.pdf.canvas.PdfCanvas;
import com.itextpdf.kernel.pdf.xobject.PdfFormXObject;

public class PdfWidgetAnnotationExample {
    public static void main(String[] args) {
        try {
            // 加载PDF文档
            PdfDocument pdfDoc = new PdfDocument(new PdfReader("input.pdf"), new PdfWriter("output.pdf"));

            // 获取第一页的第一个注释
            PdfWidgetAnnotation annotation = pdfDoc.getFirstPage().getAnnotations().get(0);

            // 创建字体对象
            PdfFont font = PdfFontFactory.createFont("Arial.ttf", "Cp1252", true);

            // 创建外观对象
            PdfFormXObject appearance = new PdfFormXObject(annotation.getRectangle());

            // 设置字体和字体大小
            PdfCanvas canvas = new PdfCanvas(appearance, pdfDoc);
            canvas.setFontAndSize(font, 12);

            // 设置注释的外观
            annotation.setNormalAppearance(appearance.getPdfObject());

            // 保存修改后的PDF文档
            pdfDoc.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}