PdfBox -更改pdf文件中的字体或fontName？

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.font.PDType1Font;

public class ChangeFontExample {
    public static void main(String[] args) {
        try (PDDocument document = PDDocument.load(new File("input.pdf"))) {
            PDPage page = document.getPage(0);
            PDPageContentStream contentStream = new PDPageContentStream(document, page, PDPageContentStream.AppendMode.OVERWRITE, true);

            // 设置新的字体和大小
            contentStream.setFont(PDType1Font.HELVETICA_BOLD, 12);

            // 写入新的文本内容
            contentStream.beginText();
            contentStream.newLineAtOffset(100, 600);
            contentStream.showText("这是新的文本内容");
            contentStream.endText();

            contentStream.close();
            document.save("output.pdf");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}