Hello Markus, thank you for providing the pdf yet again. I'll create an issue shortly. What I've found so far is that instead of using an array in the pdf a string is being used for the /Opt entry. This is not correct.
17 0 obj << /FT /Btn /Kids [61 0 R] /Opt () /T (Checkbox_unten#2) /TU (Checkbox_unten#2) /V /Off >> endobj "... If present, the Opt entry shall be an array of text strings representing the export value of each annotation in the field. ..." We are handling an empty array but we are currently not handling a string. BR Maruan Am Dienstag, dem 26.05.2026 um 10:50 +0000 schrieb Markus Mensinger via users: > Hi Maruan, > > here is the new link. It's valid for 10 Days. The document is free to > use. > > https://signotecgmbh-my.sharepoint.com/:b:/g/personal/markus_mensinger_signotec_de/IQA1G3tlspKkS5vU_AqOffDkAfs4fLjHS72BB2hRGA2wmd4?e=65ka16 > > Kind regards > Markus > > > -----Ursprüngliche Nachricht----- > > Von: [email protected] <[email protected]> > > Gesendet: Mittwoch, 20. Mai 2026 15:58 > > An: [email protected]; Markus Mensinger > > <[email protected]> > > Betreff: Re: Setting checkbox value fails when field has empty /Opt > > array > > > > Hello Markus, > > > > could you provide the test file again. I just now have the time to > > look into that and > > the link is expired. > > > > Kind regards, > > Maruan > > > > Am Dienstag, dem 28.04.2026 um 17:18 +0200 schrieb > > [email protected]: > > > 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] > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
