java - 如何正确加密合并的pdf文档

Question

我的 pdfBox API 有问题。我尝试使用以下代码加密合并的 pdf 文档:

这是合并/创建文档的功能

    public static void fillMultipleReportsInOne(List<report> reports) throws IOException {

        PDFMergerUtility PDFmerger = new PDFMergerUtility(); 
        PDDocument resultPDF = new PDDocument();

        for (report report : reports) {

            try 
            {
                PDDocument pdfDocument = PDDocument.load(new File(SRC + "test.pdf"));
                // get the document catalog
                PDAcroForm acroForm = pdfDocument.getDocumentCatalog().getAcroForm();

                // as there might not be an AcroForm entry a null check is necessary
                setFormFields(acroForm, report.getName(), report.getArea(), report.getOperatingActivities(), report.getVocationlaSchool(), report.getWeeklyTopics());
                // Save and close the filled out form.
                PDFmerger.appendDocument(resultPDF, pdfDocument);



        } catch (Exception e) {
            e.printStackTrace();
        }

    }


    encryptPDF(resultPDF, SRC + "merged.pdf");

}

这是加密函数:

 public static PDDocument encryptPDF(PDDocument pddocumentToEncrypt, String SRC) {

        // Define the length of the encryption key.
        // Possible values are 40 or 128 (256 will be available in PDFBox 2.0).
        int keyLength = 128;

        AccessPermission ap = new AccessPermission();

        // Disable printing, everything else is allowed
        ap.setCanModifyAnnotations(false);
        ap.setCanFillInForm(false);
        ap.setCanModify(false);


        // Owner password (to open the file with all permissions) is "12345"
        // User password (to open the file but with restricted permissions, is empty here) 
        StandardProtectionPolicy spp = new StandardProtectionPolicy("12334", "", ap);
        spp.setEncryptionKeyLength(keyLength);
        spp.setPermissions(ap);
        try {
            pddocumentToEncrypt.protect(spp);
            pddocumentToEncrypt.save(SRC);
            pddocumentToEncrypt.close();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return pddocumentToEncrypt;
    }

最后使用所有示例数据调用函数

report report1 = new report("TestUser1", "P&T", "operatingActivities", "weeklyTopics","vocationalSchool");
        report report2 = new report("TestUser2", "P&T2", "operatingActivities2", "weeklyTopics2","vocationalSchool2");
        report report3 = new report("TestUser3", "P&T3", "operatingActivities3", "weeklyTopics3","vocationalSchool3");
        report report4 = new report("TestUser4", "P&T4", "operatingActivities4", "weeklyTopics4","vocationalSchool4");

        List<report> reports = new ArrayList<>();
        reports.add(report1);
        reports.add(report2);
        reports.add(report3);
        reports.add(report4);

        fillMultipleReportsInOne(reports);

我的结果如下:

结果

只有第一个字段填充数据，而所有字段都应该有这绝对是一个加密问题，因为当我删除 document.protect() 行时，数据被正确填充。我还尝试了 acroForm.flatten() 函数 -> 没有成功...

也许有人遇到了同样的问题并且愿意提供帮助:)提前致谢- 亚历克斯

这是粘贴到pastebin中的整个文件: https://pastebin.com/L9auaTGH

用代码行

pddocumentToEncrypt.getDocumentCatalog().getAcroForm().refreshAppearances();

在我的加密函数中，它起作用了

Answer 1

调用

pddocumentToEncrypt.getDocumentCatalog().getAcroForm().refreshAppearances();

修复了 2.0 版本的问题。当设置/NeedAppearances 时，该版本不会在 setValue() 调用中设置外观(即表单值的视觉表示)(请参阅 PDTerminalField.applyChange())。/NeedAppearances 设置(当为 true 时)意味着查看应用程序应创建外观，以便中间的处理应用程序不需要这样做；我怀疑其中一项或多项权限设置阻止 Adob​​e Reader 在显示时对其进行更改。

另一种解决方案是调用

pdfDocument.getDocumentCatalog().getAcroForm().setNeedAppearances(false);

在设置表单值之前。

唯一未解之谜是为什么第一个值在合并文件中可见。