PDFBox：具有附件的创建PDF/A-3A文档的验证，流长度不匹配而失败

Question

我正在尝试使用示例 CreatePDFA 创建带有附加纯文本文件的 PDF/A-3A 文件，但使用 VeraPDF 验证器验证结果文件失败。 我正在使用 PDFBox v.3.0.0 RC1。

错误： 流字典中指定的 Length 键的值应与文件中紧跟在 Stream 关​​键字之后的 LINE FEED (0Ah) 字符之后以及在 endstream 关​​键字之前的 EOL 标记之前的字节数相匹配。

错误位置是： root/indirectObjects[0](22 0)/directObject[0]

如何向 PDF 文件添加正确的长度？ 附件代码如下：

    private void attachFile(PDDocument doc, File file, String mediaType, String description) throws IOException {

        long fileSize = file.length();
        BasicFileAttributes fileAttr = Files.readAttributes(file.toPath(), BasicFileAttributes.class);

        GregorianCalendar creationTimeCal = new GregorianCalendar();
        creationTimeCal.setTimeInMillis(fileAttr.creationTime().toMillis());

        GregorianCalendar modifiedTimeCal = new GregorianCalendar();
        modifiedTimeCal.setTimeInMillis(fileAttr.lastModifiedTime().toMillis());

        // embedded files are stored in a named tree
        PDEmbeddedFilesNameTreeNode efTree = new PDEmbeddedFilesNameTreeNode();

        // first create the file specification, which holds the embedded file
        PDComplexFileSpecification fs = new PDComplexFileSpecification();

        // use both methods for backwards, cross-platform and cross-language compatibility.
        fs.setFile(file.getName());
        fs.setFileUnicode(file.getName());

        COSDictionary dict = fs.getCOSObject();
        dict.setName("AFRelationship", "Alternative");

        try (InputStream is = Files.newInputStream(file.toPath(), StandardOpenOption.READ)) {

            PDEmbeddedFile ef = new PDEmbeddedFile(doc, is);

            // now lets some of the optional parameters
            ef.setSubtype(mediaType);
            ef.setSize((int) fileSize);
            ef.setCreationDate(creationTimeCal);
            ef.setModDate(modifiedTimeCal);
            ef.setDecodedStreamLength((int) fileSize);

            // use both methods for backwards, cross-platform and cross-language compatibility.
            fs.setEmbeddedFile(ef);
            fs.setEmbeddedFileUnicode(ef);
            fs.setFileDescription(StringUtils.defaultString(description, file.getName()));

            // create a new tree node and add the embedded file
            String attachmentName = StringUtils.defaultString(file.getName(),description);
            PDEmbeddedFilesNameTreeNode treeNode = new PDEmbeddedFilesNameTreeNode();
            treeNode.setNames(Collections.singletonMap(attachmentName, fs));

            // add the new node as kid to the root node
            List<PDEmbeddedFilesNameTreeNode> kids = new ArrayList<>();
            kids.add(treeNode);
            efTree.setKids(kids);

            // add the tree to the document catalog
            PDDocumentNameDictionary names = new PDDocumentNameDictionary(doc.getDocumentCatalog());
            names.setEmbeddedFiles(efTree);
            doc.getDocumentCatalog().setNames(names);

            // AF entry (Array) in catalog with the FileSpec
            COSArray cosArray = new COSArray();
            cosArray.add(fs);
            doc.getDocumentCatalog().getCOSObject().setItem("AF", cosArray);

            // show attachments panel in some viewers
            doc.getDocumentCatalog().setPageMode(PageMode.USE_ATTACHMENTS);
        }
    }

PDF文件可以在这里找到： https://gofile.io/d/FuWIdV

Answer 1

PdfBox的最新版本3.0.0-alpha2似乎解决了这个问题。