PDFBox中saveIncremental多部件表单失效问题求助

我使用PDFBox 2.0.24版本，创建了一个包含两个Widget的PDTextField，在使用saveIncremental设置字段值时无法生效。填充值并保存后，文件中的表单字段直接消失，试过不使用objectsToWrite参数也没用。

创建表单的示例代码 #

try (FileOutputStream output = new FileOutputStream("src/main/resources/Sample_form.pdf");
     PDDocument document = PDDocument.load(new File("src/main/resources/Sample.pdf"))) {

    PDFont font = PDType1Font.HELVETICA;
    PDResources resources = new PDResources();
    resources.put(COSName.HELV, font);

    PDAcroForm acroForm = new PDAcroForm(document);
    document.getDocumentCatalog().setAcroForm(acroForm);
    acroForm.setDefaultResources(resources);
    String defaultAppearanceString = "/Helv 0 Tf 0 g";
    acroForm.setDefaultAppearance(defaultAppearanceString);

    PDTextField textBox = new PDTextField(acroForm);
    textBox.setPartialName("SampleFieldMultiwidget");

    defaultAppearanceString = "/Helv 12 Tf 0 0 1 rg";
    textBox.setDefaultAppearance(defaultAppearanceString);

    acroForm.getFields().add(textBox);
    PDPage page1=document.getPage(0);
    PDPage page2=document.getPage(1);

    PDAnnotationWidget widget1 = new PDAnnotationWidget();
    PDRectangle rect = new PDRectangle(50, 750, 250, 50);
    widget1.setRectangle(rect);
    widget1.setPage(page1);
    widget1.setParent(textBox);

    PDAnnotationWidget widget2 = new PDAnnotationWidget();
    PDRectangle rect2 = new PDRectangle(200, 650, 100, 50);
    widget2.setRectangle(rect2);
    widget2.setPage(page2);
    widget2.setParent(textBox);

    List<PDAnnotationWidget> widgets = new ArrayList<>();
    widgets.add(widget1);
    widgets.add(widget2);
    textBox.setWidgets(widgets);

    widget1.setPrinted(true);
    widget2.setPrinted(true);

    page1.getAnnotations().add(widget1);
    page2.getAnnotations().add(widget2);

    document.save(output);
} catch (Exception e) {
    throw new RuntimeException(e);
}

填充字段的代码 #

try (FileOutputStream output = new FileOutputStream("src/main/resources/Sample_form_filled.pdf");
     PDDocument document = PDDocument.load(new File("src/main/resources/Sample_form.pdf"))) {
    PDAcroForm acroForm = document.getDocumentCatalog().getAcroForm();

    PDTextField field = (PDTextField)acroForm.getField("SampleFieldMultiwidget");
    field.setValue("Sample Value");
    field.setReadOnly(true);

    COSDictionary fieldDictionary = field.getCOSObject();
    fieldDictionary.setNeedToBeUpdated(true);

    COSArray cosArray = (COSArray)field.getCOSObject().getDictionaryObject(COSName.KIDS);
    cosArray.setNeedToBeUpdated(true);

    for (int i = 0; i < cosArray.size(); i++) {
        COSObject cosObject = (COSObject) cosArray.get(i);
        COSDictionary dictionary = (COSDictionary) cosObject.getDictionaryObject(COSName.AP);
        dictionary.setNeedToBeUpdated(true);
        COSStream stream = (COSStream) dictionary.getDictionaryObject(COSName.N);
        stream.setNeedToBeUpdated(true);

        COSDictionary dictionary2 = (COSDictionary) cosObject.getDictionaryObject(COSName.PARENT);
        while (dictionary2 != null) {
            dictionary2.setNeedToBeUpdated(true);
            dictionary2 = (COSDictionary) dictionary2.getDictionaryObject(COSName.PARENT);
        }
    }
    Set<COSDictionary> objectsToWrite = new HashSet<>();
    for (PDPage pdPage: document.getPages()) {
        objectsToWrite.add(pdPage.getCOSObject());
        objectsToWrite.add(field.getCOSObject());
    }
   //Added - post comment
        objectsToWrite.add(field.getWidgets().get(0).getAppearance().getCOSObject());
        objectsToWrite.add((COSDictionary) field.getWidgets().get(0).getAppearance().getNormalAppearance().getCOSObject());
        objectsToWrite.add(field.getWidgets().get(1).getAppearance().getCOSObject());
        objectsToWrite.add((COSDictionary) field.getWidgets().get(1).getAppearance().getNormalAppearance().getCOSObject());
    document.saveIncremental(output,objectsToWrite);
} catch (Exception e) {
    throw new RuntimeException(e);
}

补充信息 #

补充了示例文件

问题更新 #

问题已解决，遗漏了设置Widget外观，现在可在所有查看器中正常渲染。谢谢！

内容的提问来源于stack exchange，提问作者Vas K