Pdfbox - 添加 pdf 嵌入文件并将 PDDocument 保存到 OutputStream 不保留嵌入文件

Pdfbox - adding pdf embedded File and save the PDDocument to OutputStream does not keep the embedded Files

我正在使用 Pdfbox (1.8.8) 向 pdf 添加附件。我的问题是,当其中一个附件的类型为 .pdf 并且我将 PDDocument 保存到 OutputStream 时,最终的 pdf 文档不包含附件。如果将 PDDocument 保存到文件而不是 OutputStream 都可以正常工作,并且如果附件不包含任何 pdf,则保存到文件或 OutputStream 都可以正常工作。

我想知道是否有任何方法可以添加 pdf 嵌入文件并将 PDDocument 保存到 OutputStream,将附件保存在生成​​的最终 pdf 中。

我使用的代码是:

 private void insertAttachments(OutputStream out, ArrayList<Attachment> attachmentsResources) {

            final PDDocument doc;
            Boolean hasPdfAttach = false;
            try {
                doc = PDDocument.load(new ByteArrayInputStream(((ByteArrayOutputStream) out).toByteArray()));
                // final PDFTextStripper pdfStripper = new PDFTextStripper();
                // final String text = pdfStripper.getText(doc);
                final PDEmbeddedFilesNameTreeNode efTree = new PDEmbeddedFilesNameTreeNode();
                final Map embeddedFileMap = new HashMap();
                PDEmbeddedFile embeddedFile;
                File file = null;

                for (Attachment attach : attachmentsResources) {

                    // first create the file specification, which holds the embedded file
                    final PDComplexFileSpecification fileSpecification = new PDComplexFileSpecification();
                    fileSpecification.setFile(attach.getFilename());
                    file = AttachmentUtils.getAttachmentFile(attach);
                    final InputStream is = new FileInputStream(file.getAbsolutePath());

                    embeddedFile = new PDEmbeddedFile(doc, is);
                    // set some of the attributes of the embedded file
                    if ("application/pdf".equals(attach.getMimetype())) {
                        hasPdfAttach = true;
                    }
                    embeddedFile.setSubtype(attach.getMimetype());
                    embeddedFile.setSize((int) (long) attach.getFilesize());
                    fileSpecification.setEmbeddedFile(embeddedFile);

                    // now add the entry to the embedded file tree and set in the document.
                    embeddedFileMap.put(attach.getFilename(), fileSpecification);
                    // final String text2 = pdfStripper.getText(doc);
                }
                // final String text3 = pdfStripper.getText(doc);
                efTree.setNames(embeddedFileMap);
                // ((COSDictionary) efTree.getCOSObject()).removeItem(COSName.LIMITS); (this not work for me)
                // attachments are stored as part of the "names" dictionary in the document catalog
                final PDDocumentNameDictionary names = new PDDocumentNameDictionary(doc.getDocumentCatalog());
                names.setEmbeddedFiles(efTree);
                doc.getDocumentCatalog().setNames(names);
                // final ByteArrayOutputStream pdfboxToDocumentStream = new ByteArrayOutputStream();
                final String tmpfile = "temporary.pdf";
                if (hasPdfAttach) {
                    final File f = new File(tmpfile);
                    doc.save(f);
                    doc.close();
                     //i have try with parser but without success too
                    // PDFParser parser = new PDFParser(new FileInputStream(tmpfile));
                    // parser.parse();
                    // PDDocument doc2 = parser.getPDDocument();
                    final PDDocument doc2 = PDDocument.loadNonSeq(f, new RandomAccessFile(new File(getHomeTMP()
                            + "tempppp.pdf"), "r"));
                    doc2.save(out);
                    doc2.close();
                } else {
                    doc.save(out);
                    doc.close();
                }
                 //that does not work too
                // final InputStream in = new FileInputStream(tmpfile);
                // IOUtils.copy(in, out);
                // out = new FileOutputStream(tmpFile);
                // doc.save (out);

            } catch (IOException e1) {
                e1.printStackTrace();
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }

此致

解决方案:

private void insertAttachments(OutputStream out, ArrayList<Attachment> attachmentsResources) {

    final PDDocument doc;
    try {
        doc = PDDocument.load(new ByteArrayInputStream(((ByteArrayOutputStream) out).toByteArray()));
        ((ByteArrayOutputStream) out).reset();
        final PDEmbeddedFilesNameTreeNode efTree = new PDEmbeddedFilesNameTreeNode();
        final Map embeddedFileMap = new HashMap();
        PDEmbeddedFile embeddedFile;
        File file = null;

        for (Attachment attach : attachmentsResources) {

            // first create the file specification, which holds the embedded file
            final PDComplexFileSpecification fileSpecification = new PDComplexFileSpecification();
            fileSpecification.setFile(attach.getFilename());
            file = AttachmentUtils.getAttachmentFile(attach);
            final InputStream is = new FileInputStream(file.getAbsolutePath());

            embeddedFile = new PDEmbeddedFile(doc, is);
            // set some of the attributes of the embedded file
            embeddedFile.setSubtype(attach.getMimetype());
            embeddedFile.setSize((int) (long) attach.getFilesize());
            fileSpecification.setEmbeddedFile(embeddedFile);

            // now add the entry to the embedded file tree and set in the document.
            embeddedFileMap.put(attach.getFilename(), fileSpecification);

        }
        efTree.setNames(embeddedFileMap);
        ((COSDictionary) efTree.getCOSObject()).removeItem(COSName.LIMITS);
        // attachments are stored as part of the "names" dictionary in the document catalog
        final PDDocumentNameDictionary names = new PDDocumentNameDictionary(doc.getDocumentCatalog());
        names.setEmbeddedFiles(efTree);
        doc.getDocumentCatalog().setNames(names);
        ((COSDictionary) efTree.getCOSObject()).removeItem(COSName.LIMITS);
        doc.save(out);
        doc.close();

    } catch (IOException e1) {
        e1.printStackTrace();
    } catch (Exception e2) {
        e2.printStackTrace();
    }
}

您将新 PDF 存储在 out 中的原始 PDF 之后:

查看您的方法中 out 的所有用法:

private void insertAttachments(OutputStream out, ArrayList<Attachment> attachmentsResources) {
    ...
            doc = PDDocument.load(new ByteArrayInputStream(((ByteArrayOutputStream) out).toByteArray()));
    ...
                doc2.save(out);
    ...
                doc.save(out);

所以你得到一个 ByteArrayOutputStream 作为输入,并将其当前内容作为输入(即 ByteArrayOutputStream 不是空的,但已经包含一个 PDF),经过一些处理后,你将修改后的 PDF 附加到ByteArrayOutputStream。根据您向其展示的 PDF 查看器,您将看到原始 PDF 或经过处理的 PDF 或(非常正确的)文件是垃圾的错误消息。

如果您希望 ByteArrayOutputStream 仅包含经过处理的 PDF,只需添加

((ByteArrayOutputStream) out).reset();

或(如果您不确定流的状态)

out = new ByteArrayOutputStream();

紧接着

doc = PDDocument.load(new ByteArrayInputStream(((ByteArrayOutputStream) out).toByteArray()));

PS: 根据评论,OP 尝试对他的代码进行上述更改,但没有成功。

我不能运行问题中的代码,因为它不是self-contained。因此,我将其简化为获得 self-contained 测试的必需品:

@Test
public void test() throws IOException, COSVisitorException
{
    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    try (
            InputStream sourceStream = getClass().getResourceAsStream("test.pdf");
            InputStream attachStream = getClass().getResourceAsStream("artificial text.pdf"))
    {
        final PDDocument document = PDDocument.load(sourceStream);

        final PDEmbeddedFile embeddedFile = new PDEmbeddedFile(document, attachStream);
        embeddedFile.setSubtype("application/pdf");
        embeddedFile.setSize(10993);

        final PDComplexFileSpecification fileSpecification = new PDComplexFileSpecification();
        fileSpecification.setFile("artificial text.pdf");
        fileSpecification.setEmbeddedFile(embeddedFile);

        final Map<String, PDComplexFileSpecification> embeddedFileMap = new HashMap<String, PDComplexFileSpecification>();
        embeddedFileMap.put("artificial text.pdf", fileSpecification);

        final PDEmbeddedFilesNameTreeNode efTree = new PDEmbeddedFilesNameTreeNode();
        efTree.setNames(embeddedFileMap);

        final PDDocumentNameDictionary names = new PDDocumentNameDictionary(document.getDocumentCatalog());
        names.setEmbeddedFiles(efTree);
        document.getDocumentCatalog().setNames(names);

        document.save(baos);
        document.close();
    }
    Files.write(Paths.get("attachment.pdf"), baos.toByteArray());
}

如您所见,此处的 PDFBox 仅使用流。结果:

因此,PDFBox 可以毫无问题地存储嵌入了 PDF 文件附件的 PDF。

因此,该问题很可能与此工作流程本身无关