在PDFBox中编写多行和多页-获取PDPageContentStream Y轴

import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDPageTree;
import org.apache.pdfbox.pdmodel.PDRectangle;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.common.PDStream;
import org.apache.pdfbox.pdmodel.font.PDType1Font;

import java.io.IOException;

public class PDFFontExample {
    public static void main(String[] args) {
        try {
            PDDocument document = new PDDocument();
            PDPage page = new PDPage(PDRectangle.A4);
            document.addPage(page);

            PDPageContentStream contentStream = new PDPageContentStream(document, page);

            PDType1Font font = PDType1Font.HELVETICA_BOLD;
            int fontSize = 12;
            float leading = 1.5f * fontSize;

            contentStream.setFont(font, fontSize);
            contentStream.setLeading(leading);

            float margin = 50;
            float startX = margin;
            float startY = page.getMediaBox().getHeight() - margin;

            String text = "This is a sample text.";
            String longText = "This is a very long sample text that will wrap to the next line because it exceeds the page width.";

            contentStream.beginText();
            contentStream.newLineAtOffset(startX, startY);
            contentStream.showText(text);
            contentStream.newLine();

            // Get the Y-axis coordinate after writing the first line
            float newY = contentStream.getCurrentPoint().getY();

            contentStream.showText(longText);
            contentStream.endText();
            contentStream.close();

            document.save("example.pdf");
            document.close();

            System.out.println("PDF created successfully.");
            System.out.println("Y-axis coordinate after writing the first line: " + newY);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}