以编程方式合并加密的 pdf 文件例外

Question

我一直在使用以下代码以编程方式合并加密的pdf文件。

public void mergeMyFiles(String filesToBeMerged[], String mergedFileLocation, String password) {
    try {
        int pageOffset = 0;
        ArrayList masterBookMarkList = new ArrayList();

        int fileIndex = 0;
        String outFile = mergedFileLocation;
        Document document = null;
        PdfCopy writer = null;
        PdfReader reader = null;
        PdfReader.unethicalreading = true;
        for (fileIndex = 0; fileIndex < filesToBeMerged.length; fileIndex++) {
            /**
             * Create a reader for the file that we are reading
             */
            reader = new PdfReader(filesToBeMerged[fileIndex], password.getBytes());
            /**
             * Replace all the local named links with the actual destinations.
             */
            reader.consolidateNamedDestinations();

            /**
             * Retrieve the total number of pages for this document
             */
            int totalPages = reader.getNumberOfPages();

            /**
             * Get the list of bookmarks for the current document
             * If the bookmarks are not empty, store the bookmarks
             * into a master list
             */
            List bookmarks = SimpleBookmark.getBookmark(reader);
            if (bookmarks != null) {
                if (pageOffset != 0)
                    SimpleBookmark.shiftPageNumbers(bookmarks, pageOffset,
                        null);
                masterBookMarkList.addAll(bookmarks);
                System.out.println("Bookmarks found and storing...");
            } else {
                System.out.println("No bookmarks in this file...");
            }
            pageOffset += totalPages;

            /**
             * Merging the files to the first file.
             * If we are passing file1, file2 and file3,
             * we will merge file2 and file3 to file1.
             */
            if (fileIndex == 0) {
                /**
                 * Create the document object from the reader
                 */
                document = new Document(reader.getPageSizeWithRotation(1));

                /**
                 * Create a pdf write that listens to this document.
                 * Any changes to this document will be written the file
                 *
                 * outFile is a location where the final merged document
                 * will be written to.
                 */

                System.out.println("Creating an empty PDF...");
                writer = new PdfCopy(document, new FileOutputStream(outFile));
                /**
                 * Open this document
                 */
                document.open();
            }
            /**
             * Add the conent of the file into this document (writer).
             * Loop through multiple Pages
             */
            System.out.println("Merging File: " + filesToBeMerged[fileIndex]);
            PdfImportedPage page;
            for (int currentPage = 1; currentPage <= totalPages; currentPage++) {
                page = writer.getImportedPage(reader, currentPage);
                writer.addPage(page);
            }

            /**
             * This will get the documents acroform.
             * This will return null if no acroform is part of the document.
             *
             * Acroforms are PDFs that have been turned into fillable forms.
             */
            System.out.println("Checking for Acroforms");
            PRAcroForm form = reader.getAcroForm();
            if (form != null) {
                //writer.copyAcroForm(reader);
                writer.addDocument(reader);
                System.out.println("Acroforms found and copied");
            } else
                System.out.println("Acroforms not found for this file");

            System.out.println();
        }
        /**
         * After looping through all the files, add the master bookmarklist.
         * If individual PDF documents had separate bookmarks, master bookmark
         * list will contain a combination of all those bookmarks in the
         * merged document.
         */
        if (!masterBookMarkList.isEmpty()) {
            writer.setOutlines(masterBookMarkList);
            System.out.println("All bookmarks combined and added");

        } else {
            System.out.println("No bookmarks to add in the new file");

        }

        /**
         * Finally Close the main document, which will trigger the pdfcopy
         * to write back to the filesystem.
         */
        document.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

最近，我在试图创建pdfReader时，在下面这行代码中发现了这个错误:

reader = new PdfReader(filesToBeMerged[fileIndex], password.getBytes());

com.itextpdf.text.exceptions。无效PdfException:未知加密类型R=6，位于com.itextpdf.text.pdf.PdfReader.readPdf（PdfReaders.java:738位于android.os.Handler.dispatchMessage的com.project.mainPageShop$DownloadFileAsync.onPostExecute（mainPageShop.java:11757android.app.ActivityThread.main（ActivityThread.java:7814）上的android.os.Looper.loop（Looper.java:237），java.lang.reflect.Method。在com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run（RuntimeInit.java:493）在com.anderoid.internall.os.ZygoteInit.main（Zygote Init.java:1068）调用（本机方法）

请注意，密码是正确的，并且使用此代码工作的同一文件现在正在引发此异常。

更新：

我使用com.itextpdf使用了以下代码:itext7-core:7.0.2

public void mergePDFFiles(String FILE1, String FILE2, String mergedFileLocation, String password) {
    try {
        PdfReader pdf1 = new PdfReader(FILE1);
        pdf1.setUnethicalReading(true);
        PdfReader pdf2 = new PdfReader(FILE2);
        pdf2.setUnethicalReading(true);
        PdfDocument pdfDocument = new PdfDocument(pdf1, new PdfWriter(mergedFileLocation));
        PdfDocument pdfDocument2 = new PdfDocument(pdf2);

        PdfMerger merger = new PdfMerger(pdfDocument);
        merger.merge(pdfDocument2, 1, pdfDocument2.getNumberOfPages());

        pdfDocument2.close();
        pdfDocument.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

这是logcat的结果:

致命例外：主要进程：mainPageShop.java:11788，PID： 7665com.project.mainPageShop：未知加密类型R==6。在DownloadFileAsync.onPostExecute（mainPageShop.java:11659）在android.os.AsyncTask.finish（AsyncTask.java:755）在android.os.AsyncTask.access（AsyncTask.java:192）在android.os.AsyncTask（InternalHandler.handleMessage）在AsyncTask.java:772（android.os.Handler.dispatchMessage）在Handler.java:107（PdfDocument.java:281）在com.itextpdf.kernel.pdf.PdfDocument.（PdfDocument.java:249）在com.project.mainPageShop.mergePDFFiles（mainPageShop.java:4353）在com.neelwafurat.iKitabForAndroid.mainPageShop$DownloadFileAsync.onPostExecute（com.project）在com.itextpdf.kernel.PdfException$com.itextpdf.kernel.pdf.PdfEncryption.readAndSetCryptoModeForStdHandler（PdfEncryption.java:508）在com.itextpdf.kernel.pdf.PdfEncryption.（PdfEncryption.java:181）在com.itextpdf.kernel.pdf.PdfReader.readDecryptObj900美元（PdfReader.java:1061）在com.itextpdf.kernel.pdf.PdfReader.readPdf$PdfReader.java:531（com.itextpdf.kernel.pdf.PdfDocument.open）在PdfDocument.java:1585（com.itextpdf.kernel.pdf.PdfDocument.）在android. os. Looper. Loop（Looper. java： 237）在java. lang. app. ActivityThread. main（ActivityThread. java： 7814）在com. android. interal. os. RuntimeInit$MachodAndArgsCaller. run（RuntimeInit. java： 493）在com. android. interal. os. ZygoteInit. main（ZygoteInit. java： 1068）

错误发生在以下行：

PdfDocument pdfDocument = new PdfDocument(pdf1, new PdfWriter(mergedFileLocation));

在下面找到密码为123456的加密pdf文件的链接

https://small pdf . com/shared # ST = 8921059d-6615-4264-a3 F6-c76d 476 DC 168

https://smallpdf.com/shared#st=7d3c11c7-b34d-4399-bc03-c66b7be788d0

Answer 1

iText 5或iText 7.0.2不支持标准安全处理程序的修订版6。它是在支持PDF 2.0的上下文中在iText 7.1.0中引入的。

我稍微调整了一下你的代码样本来测试。请注意，您没有将密码传递给< code>PdfReader实例。

还要注意，您为示例PDF共享的密码（123456）是用户密码，而不是所有者密码。

用户密码，也称为打开密码，用于打开PDF文档，即授予对内容的访问权限。所有其他限制都由所有者密码（也称为权限密码）处理，例如允许/阻止打印文档。

对于您的示例文档，打开密码和权限密码都设置了：

如果您有可用的所有者密码，您应该在处理PDF时使用它，即将其传递给PdfReader实例。这使您可以避免非道德阅读设置。

测试代码：

public void mergePDFFiles(String FILE1, String FILE2, String mergedFileLocation, String password)
{
    try {
        PdfReader pdf1 = new PdfReader(FILE1,
            new ReaderProperties().setPassword(password.getBytes()));
        pdf1.setUnethicalReading(true);
        PdfReader pdf2 = new PdfReader(FILE2,
            new ReaderProperties().setPassword(password.getBytes()));
        pdf2.setUnethicalReading(true);
        PdfDocument pdfDocument = new PdfDocument(pdf1, new PdfWriter(mergedFileLocation));
        PdfDocument pdfDocument2 = new PdfDocument(pdf2);

        PdfMerger merger = new PdfMerger(pdfDocument);
        merger.merge(pdfDocument2, 1, pdfDocument2.getNumberOfPages());

        pdfDocument2.close();
        pdfDocument.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
}

iText 7.0.2 不支持修订版 6，您已经注意到：

Exception in thread "main" com.itextpdf.kernel.PdfException: Unknown encryption type R == 6.
    at com.itextpdf.kernel.pdf.PdfEncryption.readAndSetCryptoModeForStdHandler(PdfEncryption.java:508)
    at com.itextpdf.kernel.pdf.PdfEncryption.<init>(PdfEncryption.java:181)
    at com.itextpdf.kernel.pdf.PdfReader.readDecryptObj(PdfReader.java:1061)
    at com.itextpdf.kernel.pdf.PdfReader.readPdf(PdfReader.java:531)
    at com.itextpdf.kernel.pdf.PdfDocument.open(PdfDocument.java:1585)
    at com.itextpdf.kernel.pdf.PdfDocument.<init>(PdfDocument.java:281)
    at com.itextpdf.kernel.pdf.PdfDocument.<init>(PdfDocument.java:249)

从iText 7.1.0到当前版本(7.1.13)，您的两个示例文件将正确合并，产生一个4页的输出文件。