java - APache pdf box：定义动态页面的页面大小

Question

如何定义动态页面的页面大小？我创建了 A4 大小的页面并添加到 PDDocument。第一页按预期工作，但第二页的唯一问题。

public class PdfBoxSample01{
               
    public static void main(String[] args) throws IOException {
        PDDocument document = new PDDocument();
        PDPage pdPag = new PDPage(PDRectangle.A4);
        document.addPage(pdPag);
        try {
            PDPageContentStream contentStream = new PDPageContentStream(document, pdPag, true, true);
            BaseTable parentTable = createParentTable(document, pdPag);
   }    
}

private static BaseTable createParentTable(PDDocument document, PDPage page) {
    float yCordinate = page.getCropBox().getUpperRightY() - 30;
    float margin = 50;
    // starting y position is whole page height subtracted by top and bottom margin
    float yStartNewPage = page.getMediaBox().getHeight() - (2 * margin);
    // we want table across whole page width (subtracted by left and right margin ofcourse)
    float tableWidth = page.getMediaBox().getWidth() - (2 * margin);

    boolean drawContent = true;
    float bottomMargin = 70;
    // y position is your coordinate of top left corner of the table
    float yPosition = yCordinate;

    BaseTable table = null;
    try {
        table = new BaseTable(yPosition, yStartNewPage,
        bottomMargin, tableWidth, margin, document, page, true, drawContent);
    } catch (IOException e) {
        e.printStackTrace();
    }
    return table;
}