在pdf版本1.2中，只有在新版本中创建pdfstamper（new pdfstamper（reader，fos'\0'，true）-最后一个参数负责新版本）时，才会放置戳记，但当您尝试以戳记pdf格式创建新的com.aspose.pdf.document（contentfilepath）时，会崩溃：

Caused by: java.lang.NullPointerException
 at com.aspose.pdf.internal.l1if.l1v.<init>(Unknown Source)
 at com.aspose.pdf.internal.l6if.lf.lf(Unknown Source)
 at com.aspose.pdf.internal.l0h.l0p.lj(Unknown Source)
 at com.aspose.pdf.PageCollection.<init>(Unknown Source)
 at com.aspose.pdf.ADocument.l1h(Unknown Source)
 at com.aspose.pdf.ADocument.lI(Unknown Source)
 at com.aspose.pdf.ADocument.<init>(Unknown Source)
 at com.aspose.pdf.Document.<init>(Unknown Source)

在调试中，我在页面集合中看到suppressedexception错误unmodifiablerandomaccesslist
不幸的是，我不能附加的pdf文件，因为它的机密数据。如第20.10节，第5.0.5节。

PdfStamper stamper = null;
FileOutputStream fos = null;
PdfReader reader = null;
String contentFilePathOut = "C:\\DISTR\\out.pdf";
try {
    FileInputStream fis = new FileInputStream("C:\\DISTR\\source.pdf");
    reader = new PdfReader(fis);
    fos = new FileOutputStream(contentFilePathOut, true);
    stamper = new PdfStamper(reader, fos, '\0', true);
    PdfContentByte canvas = stamper.getOverContent(1);
    ColumnText.showTextAligned(canvas, Element.ALIGN_LEFT, new Phrase("Hello people!"), 250, 750, 0);
} finally {
    try {
        if (stamper != null) {
            stamper.close();
        }
    } catch (Exception ignore) {
    }

    try {
        if (fos != null) {
            fos.close();
        }
    } catch (Exception ignore) {

    }
    try {
        if (reader != null) {
            reader.close();
        }
    } catch (Exception ignore) {
    }
}
try {
    com.aspose.pdf.Document pdf = new com.aspose.pdf.Document(contentFilePathOut);
} catch (Exception e) {
    throw new ServiceException(e);
}