title: Verifying integrity of documents
body: <p>What are the steps to verify integrity of these documents ? <code>doc,docx,docm,odt,rtf,pdf,odf,odp,xls,xlsx,xlsm,ppt,pptm</code>  </p>
  
  <p>Or at least of some of them. Usually when uploaded to a content repository.</p>
  
  <p>I guess that inputStream is always 99,99% read properly from MultiPart http request otherwise exception would be thrown and action taken. But user can upload already corrupted file - do I use third party libraries for checking that? I didn't see anything like that in odftoolkit, itextpdf, pdfbox, apache poi or tika</p>