Hi Markus: from the 1.7 spec:
"... If present, the Opt entry shall be an array of text strings representing the export value of each annotation in the field. ..." So it's present but does not contain any value but the spec has "... shall be ..." which means an empty array is not permitted here. We are looking into handling it on the PDFBox side but I thought it might be good to check if the template creation can be enhanced. BR Maruan Am Dienstag, dem 28.04.2026 um 15:09 +0000 schrieb Markus Mensinger: > Hi Maruan, > > the document is free to use. Acrobat Preflight found no syntax > errors. Which tool are you using to check it? > > I'll find out which program was used to create the document and let > you know if I find out. > > Kind regards > Markus > > > > -----Ursprüngliche Nachricht----- > > Von: [email protected] <[email protected]> > > Gesendet: Dienstag, 28. April 2026 12:45 > > An: [email protected] > > Cc: Markus Mensinger <[email protected]> > > Betreff: Re: Setting checkbox value fails when field has empty /Opt > > array > > > > Hello Markus, > > > > we can look at making PDFBox handling this. OTOH the file itself is > > not spec > > compliant. Do you know what tool has generated this PDF?. > > > > "... Each entry shall be a text string representing the on state of > > the corresponding > > widget annotation.". We can look at handling that gracefully. > > > > When creating a ticket can we add the file to the ticket? > > > > BTW: the workaround you documented looks fine for now > > > > BR > > Maruan > > > > > > Am Dienstag, dem 28.04.2026 um 10:12 +0000 schrieb Markus Mensinger > > via > > users: > > > > > > > > > > > > Hi PdfBox Team, > > > > > > we have a problem with a customer document. > > > Download: > > > pdf-Symbol form_with_checkbox.pdf > > > Link valid until 08.05. > > > > > > Here is a bug report generated with Claude Sonnet. > > > > > > > > > Component: PDFBox - Interactive Forms (AcroForm) Affects Version: > > > 3.0.7 > > > Type: Bug > > > > > > > > > SUMMARY > > > > > > When a checkbox field in an AcroForm PDF contains an empty /Opt > > > array > > > (/Opt []) in its field dictionary, calling > > > PDCheckBox.setValue("Yes") > > > throws an IllegalArgumentException, even though "Yes" is a > > > perfectly > > > valid export value defined by the field's appearance states. > > > > > > The same field can be checked and unchecked without any error > > > using > > > Adobe Acrobat products (Acrobat Reader, Acrobat Pro), which treat > > > the > > > empty /Opt array as if it were absent. This confirms that the PDF > > > is > > > valid and the issue is specific to PDFBox's validation logic. > > > > > > > > > ERROR MESSAGE > > > > > > java.lang.IllegalArgumentException: value 'Yes' is not a valid > > > option > > > for the field Check_Info_Post_andere, valid values are: [] and > > > Off > > > > > > > > > ROOT CAUSE > > > > > > The validation in PDCheckBox.setValue() checks the /Opt array > > > when it > > > is present. > > > If the array exists but is empty, all non-"Off" values are > > > rejected - > > > including the export value "Yes" that is defined in the field's > > > appearance dictionary (/AP). > > > The empty /Opt array should either be ignored or treated as > > > absent - > > > which is exactly what Adobe Acrobat does. > > > > > > > > > STEPS TO REPRODUCE > > > > > > import org.apache.pdfbox.Loader; > > > import org.apache.pdfbox.cos.COSArray; import > > > org.apache.pdfbox.cos.COSName; import > > > org.apache.pdfbox.pdmodel.PDDocument; > > > import org.apache.pdfbox.pdmodel.interactive.form.PDCheckBox; > > > import org.apache.pdfbox.pdmodel.interactive.form.PDField; > > > > > > import java.io.File; > > > > > > public class CheckBoxBugDemo { > > > > > > public static void main(String[] args) { > > > try (PDDocument doc = Loader.loadPDF(new > > > File("form_with_checkbox.pdf"))) { > > > > > > PDField field = doc.getDocumentCatalog() > > > .getAcroForm() > > > > > > .getField("Check_Info_Post_andere"); > > > > > > System.out.println("Field type : " + > > > field.getFieldType()); > > > System.out.println("/Opt entry : " + > > > field.getCOSObject().getItem(COSName.OPT)); // > > > prints: COSArray{} > > > > > > // Workaround: manually remove the empty /Opt array > > > before > > > setting value > > > COSArray opt = (COSArray) > > > field.getCOSObject().getDictionaryObject(COSName.OPT); > > > if (opt != null && opt.size() == 0) { > > > field.getCOSObject().removeItem(COSName.OPT); > > > System.out.println("/Opt removed (was empty)"); > > > } > > > > > > // Without the workaround above, this line throws > > > IllegalArgumentException: > > > // "value 'Yes' is not a valid option ... valid > > > values > > > are: [] and Off" > > > ((PDCheckBox) field).setValue("Yes"); > > > > > > System.out.println("Value set successfully: " + > > > ((PDCheckBox) field).getValue()); > > > > > > } catch (Exception e) { > > > e.printStackTrace(); > > > } > > > } > > > } > > > > > > > > > EXPECTED BEHAVIOR > > > > > > An empty /Opt array should be treated the same as a missing /Opt > > > entry. The value "Yes" (or any export value present in the > > > field's > > > appearance states) should be accepted. This is consistent with > > > how > > > Adobe Acrobat Reader and Acrobat Pro handle this case. > > > > > > > > > ACTUAL BEHAVIOR > > > > > > PDCheckBox.setValue("Yes") throws IllegalArgumentException > > > because the > > > empty /Opt array causes the valid-options check to return an > > > empty > > > list, which excludes "Yes". > > > > > > > > > WORKAROUND > > > > > > Remove the empty /Opt entry from the field dictionary before > > > calling > > > setValue(): > > > > > > COSArray opt = (COSArray) > > > field.getCOSObject().getDictionaryObject(COSName.OPT); > > > if (opt != null && opt.size() == 0) { > > > field.getCOSObject().removeItem(COSName.OPT); > > > } > > > ((PDCheckBox) field).setValue("Yes"); > > > > > > > > > SUGGESTED FIX > > > > > > In the PDFBox source, the method that validates allowed values > > > for a > > > checkbox should skip or ignore the /Opt array when it is present > > > but > > > empty (size() == 0), bringing the behavior in line with Adobe > > > Acrobat. > > > > > > > > > Kind regards > > > Markus > > > --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
