title: How to check PDF/A conformance of existing document with iText 7?
body: <p>I'm trying to check the conformance (PDF/A-1B) of an existing PDF document with iText. Unfortunately it only checks the conformance for newly created elements in document but ignores existing parts of document.</p>
  
  <pre><code>byte[] pdf = ...; // pdf document which claims to be conform but is not conform (1 font is not embedded)
  final PdfADocument pdfADocument = new PdfADocument(new PdfReader(new ByteArrayInputStream(pdf)), 
       new PdfWriter(new ByteArrayOutputStream()));
  
  pdfADocument.close();
  </code></pre>
  
  <p>If I add something not conform to <code>pdfADocument</code> then the call to <code>close()</code> throws a <code>PdfAConformanceException</code>.</p>
  
  <p>I only find example about creating documents with PDF/A conformance but no example about just validating an existing document.</p>
  
  <p>Is there a way to check conformance with iText 7 for an existing document?</p>