title: Creating a single PDF file from multiple templates with iText
body: <p>I have the following piece of code that would open a PDF template, fill the AcroFields with data from the <code>Receipt</code> object and output to the browser. It works perfect with one instance of my Receipt but now I one to repeat the process with a List of Receipts so that I can produce a single PDF file concatenating the pdf stamper instances.</p>
  
  <p>This is my code right now:</p>
  
  <pre><code>response.setContentType("application/pdf");
  
  PdfReader pdfTemplate = new PdfReader ("/receipt-template.pdf");
  PdfStamper stamper = new PdfStamper(pdfTemplate, response.getOutputStream());
  stamper.setFormFlattening(true);
  AcroFields form = stamper.getAcroFields();
  
  // fill the fields as
  form.setField("number", recipt.getNumber().toString());
  
  // ...
  stamper.close();
  pdfTemplate.close();
  </code></pre>
  
  <p>I would like to do something like:</p>
  
  <pre><code>pdf = new pdf
  foreach receipt in receiptsList
      partial = fillReceiptTemplate (receipt)
      pdf.append (partial)
  output pdf
  </code></pre>
  
  <p>Is it possible? I've read in some forums that I should use <code>PdfCopy</code> or <code>PdfSmartCopy</code> but I have no clue how, in other places says that's not possible to concatenate the whole pdf document so I should add pages instead..</p>