如何在 PdfBox 中显示 Creator 的签名详情

Question

我想在签名详细信息中显示创作者。在“签名是使用不可用创建的。”

这是我添加标志信息的代码：

private void signDetached(SignatureInterface signature, PDDocument document, OutputStream output) throws IOException {
    PDSignature pdSignature = new PDSignature();
    pdSignature.setFilter(PDSignature.FILTER_ADOBE_PPKLITE);
    pdSignature.setSubFilter(PDSignature.SUBFILTER_ADBE_PKCS7_DETACHED);
    pdSignature.setName("jvmfy");
    pdSignature.setReason("Learn how to sign pdf with jvmfy.com!");

    // the signing date, needed for valid signature
    pdSignature.setSignDate(Calendar.getInstance());

    // register signature dictionary and sign interface
    document.addSignature(pdSignature, signature);

    // write incremental (only for signing purpose)
    // use saveIncremental to add signature, using plain save method may break up a document
    document.saveIncremental(output);
}

Answer 1

我在 PDF 32000 specification 中查找 Prop_Build。这在 PDFBox 示例中没有实现，在搜索“PDF Signature Build Dictionary Specification”后，我认为它令人困惑。但根据我在现有签名 PDF 中看到的内容，此尝试有效：

COSDictionary pbDict = new COSDictionary();
COSDictionary appDict = new COSDictionary();
appDict.setName(COSName.NAME, "PDFBox");
pbDict.setItem(COSName.getPDFName("App"), appDict);
pdSignature.getCOSObject().setItem(COSName.getPDFName("Prop_Build"), pbDict);

如何在 PdfBox 中显示 Creator 的签名详情

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