使用PDFBox将PDF转换为PDF / A

Question

目前我正在尝试将PDF转换为PDF / A.

然而不知怎的，我不知道我是否可以通过这种方式转换色彩空间？

这是我的代码，但是：

PDDocumentInformation info = doc.getDocumentInformation();
System.out.println("Page Count=" + doc.getNumberOfPages());
System.out.println("Title=" + info.getTitle());
System.out.println("Author=" + info.getAuthor());
System.out.println("Subject=" + info.getSubject());
System.out.println("Keywords=" + info.getKeywords());
System.out.println("Creator=" + info.getCreator());
System.out.println("Producer=" + info.getProducer());
System.out.println("Creation Date=" + info.getCreationDate());
System.out.println("Modification Date=" + info.getModificationDate());
System.out.println("Trapped=" + info.getTrapped());


PDDocumentCatalog cat = doc.getDocumentCatalog();
XMPMetadata xmp = XMPMetadata.createXMPMetadata();

PDFAIdentificationSchema pdfaid = xmp.createAndAddPFAIdentificationSchema();
pdfaid.setConformance("A");
pdfaid.setPart(3);
pdfaid.setAboutAsSimple(null);


DublinCoreSchema dublinCoreSchema = xmp.createAndAddDublinCoreSchema();
dublinCoreSchema.setTitle(info.getTitle());

dublinCoreSchema.addCreator(info.getAuthor());


AdobePDFSchema adobePDFSchema = xmp.createAndAddAdobePDFSchema();
adobePDFSchema.setProducer(info.getProducer());


XMPBasicSchema xmpBasicSchema = xmp.createAndAddXMPBasicSchema();
xmpBasicSchema.setCreatorTool(info.getCreator());
xmpBasicSchema.setCreateDate(info.getCreationDate());
xmpBasicSchema.setModifyDate(info.getModificationDate());

xmp.addSchema(pdfaid);
XmpSerializer serializer = new XmpSerializer();
ByteArrayOutputStream baos = new ByteArrayOutputStream();
serializer.serialize(xmp, baos, true);


InputStream colorProfile = PdfConverter.class.getResourceAsStream("/sRGBColorSpaceProfile.icm");
PDOutputIntent oi = new PDOutputIntent(doc, colorProfile);

oi.setInfo("sRGB IEC61966-2.1");
oi.setOutputCondition("sRGB IEC61966-2.1");
oi.setOutputConditionIdentifier("sRGB IEC61966-2.1");
oi.setRegistryName("http://www.color.org");


cat.addOutputIntent(oi);
PDMetadata metadata = new PDMetadata(doc);
metadata.importXMPMetadata(baos.toByteArray());
cat.setMetadata(metadata);

颜色空间被添加但是在验证时我得到：

2.3.2 : Unexpected key in Graphic object definition, The ColorSpace is unknown

对于每个页面/元素，它经常出现。

我可以做任何反对吗？喜欢转换ColorsSpace？使用antoher库？