title: How to convert a BLOB to pdf or csv using itext
body: <p>My goal is to display the appropriate file, when the user clicks on a pdf or xls link.
  The contents of a pdf or xlsfile are stored as a blob in a table. A stored procedure takes the file id as an input parameter and returns the blob as output.
  I want to be able to display the file and am not sure how to go about it. On doing some reading it looks like i could use itest.
  Is there a way to convert the blob to a pdf(or xls), using itext. Is this possible?
  I was unable to find any examples that use a blob datatype.</p>