使用 java 检查 pdf PDF/A-1A 时出现 iText 错误

Question

我写的是在使用 Java iText 库版本 5.5.3 签署具体的 pdf 文件时遇到的一个错误。

Adobe Pro 验证一致性并告诉我一致性已经验证，但 iText 告诉我“/Widget 类型的注释应该有 Contents 键”。

您可以在http://www.boe.es/boe/dias/2014/08/06/pdfs/BOE-A-2014-8500.pdf获取具体文件

我在我得到的跟踪下面发布：

Caused by: com.itextpdf.text.pdf.PdfAConformanceException: Annotation of type /Widget should have Contents key.
at com.itextpdf.text.pdf.internal.PdfA1Checker.checkAnnotation(PdfA1Checker.java:462)
at com.itextpdf.text.pdf.internal.PdfAChecker.checkPdfAConformance(PdfAChecker.java:219)
at com.itextpdf.text.pdf.internal.PdfAConformanceImp.checkPdfIsoConformance(PdfAConformanceImp.java:71)
at com.itextpdf.text.pdf.PdfWriter.checkPdfIsoConformance(PdfWriter.java:3426)
at com.itextpdf.text.pdf.PdfWriter.checkPdfIsoConformance(PdfWriter.java:3422)
at com.itextpdf.text.pdf.PdfAnnotation.toPdf(PdfAnnotation.java:999)
at com.itextpdf.text.pdf.PdfIndirectObject.writeTo(PdfIndirectObject.java:158)
at com.itextpdf.text.pdf.PdfWriter$PdfBody.write(PdfWriter.java:420)
at com.itextpdf.text.pdf.PdfWriter$PdfBody.add(PdfWriter.java:398)
at com.itextpdf.text.pdf.PdfWriter$PdfBody.add(PdfWriter.java:373)
at com.itextpdf.text.pdf.PdfWriter$PdfBody.add(PdfWriter.java:369)
at com.itextpdf.text.pdf.PdfWriter.addToBody(PdfWriter.java:843)
at com.itextpdf.text.pdf.PdfStamperImp.addAnnotation(PdfStamperImp.java:1389)
at com.itextpdf.text.pdf.PdfStamperImp.addAnnotation(PdfStamperImp.java:1401)
at com.itextpdf.text.pdf.PdfSignatureAppearance.preClose(PdfSignatureAppearance.java:1283)

提前感谢您的回复。

Answer 1

我已尝试将此处（http://itextpdf.com/book/digitalsignatures20130304.pdf，第 29 页）的示例应用到您的 PDF 文档，一切似乎都运行良好。 代码中唯一的例外是：

1. 创建 PdfAStamper 而不是 PdfStamper：

   PdfAStamper stamper = PdfAStamper.createSignature(reader, os, '\0', PdfAConformanceLevel.PDF_A_1B);
   

2. 将字体设置为 PdfSignatureAppearance 以便可以嵌入字体：

   appearance.setLayer2Font(FontFactory.getFont("FreeMonoBold.ttf", BaseFont.WINANSI, BaseFont.EMBEDDED, 12));
   

3. 设置输出意图：

   ICC_Profile icc = ICC_Profile.getInstance(new FileInputStream("sRGB Color Space Profile.icm"));
   stamper.getWriter().setOutputIntents("Custom", "", "http://www.color.org", "sRGB IEC61966-2.1", icc);
   

这是一个完整的代码：

static public void sign(String src, String dest, Certificate[] chain, PrivateKey pk, String digestAlgorithm, String provider, MakeSignature.CryptoStandard subfilter, String reason, String location) throws GeneralSecurityException, IOException, DocumentException {
    // Creating the reader and the stamper
    PdfReader reader = new PdfReader(src);
    FileOutputStream os = new FileOutputStream(dest);
    PdfAStamper stamper = PdfAStamper.createSignature(reader, os, '\0', PdfAConformanceLevel.PDF_A_1B);
    // Creating the appearance
    PdfSignatureAppearance appearance = stamper.getSignatureAppearance();
    appearance.setLayer2Font(FontFactory.getFont("FreeMonoBold.ttf", BaseFont.WINANSI, BaseFont.EMBEDDED, 12));
    appearance.setReason(reason);
    appearance.setLocation(location);
    appearance.setVisibleSignature(new Rectangle(36, 748, 144, 780), 1, "sig");
    ICC_Profile icc = ICC_Profile.getInstance(new FileInputStream("sRGB Color Space Profile.icm"));
    stamper.getWriter().setOutputIntents("Custom", "", "http://www.color.org", "sRGB IEC61966-2.1", icc);
    // Creating the signature
    ExternalDigest digest = new BouncyCastleDigest();
    ExternalSignature signature = new PrivateKeySignature(pk, digestAlgorithm, provider);
    MakeSignature.signDetached(appearance, digest, signature, chain, null, null, null, 0, subfilter);
}

但您的用例可能有点不同。也许您设置了特殊选项或其他东西...您能否提供失败的示例代码？