From java.awt.print.Pageable to PDF

My current project has implemented multi-page printing, with headers and footers and all that.  It's complex.  We use some of the ideas from Stanislav Lapitsky and his series of articles about a PaginationPrinter.  If a user wants the printouts not on paper, but as PDF files, we suggest that they use a free utility like CutePDF.  (there are alternatives)

However, CutePDF is Windows only, and it's a couple of extra steps as they have to remember to select the correct "printer", then enter a filename.  Also, there may be a future need to append output from a collection of data into a single output PDF file.

So, a cross-platform, java-centric way to "print" our results by creating a PDF file would be a good option.  Fortunately, iText offers everything we need, in fact, way more than we need, and you can get an excellent book iText in Action.

Some Googling for help was tricky, cause, if you Google for something like "java print PDF" you get lots of links on how to open and print an existing PDF document.  We want to create a PDF document.  More searching led to an excellent blogpost by Gert-Jan Schoeten, "From java.awt.print.Printable to PDF".  You would not do too poorly by skipping the rest of my blog and just going to his.  However, by using more information from Pageable and Printable you can slightly simplify his code.  The way I set things up and return the results is, IMO, slightly preferable, but still largely a matter of style.  I am largely glossing over the whole FontMapper issue as well, since my project uses only basic fonts.

Here's the code:

package com.flyingspaniel.pdf;

import java.awt.Graphics2D;
import java.awt.print.PageFormat;
import java.awt.print.Pageable;
import java.awt.print.Printable;
import java.awt.print.PrinterException;
import java.io.IOException;
import java.io.OutputStream;


// if you change to iText v5 these imports change to com.itextpdf...

import com.lowagie.text.Document;
import com.lowagie.text.DocumentException;
import com.lowagie.text.Rectangle;
import com.lowagie.text.pdf.DefaultFontMapper;
import com.lowagie.text.pdf.FontMapper;
import com.lowagie.text.pdf.PdfContentByte;
import com.lowagie.text.pdf.PdfWriter;

/**
 * With this class, you can print a {@link Pageable} to a pdf
 *
 * @author Morgan Conrad
 *
 * Based upon earlier work by
 * @author G.J. Schouten
 * @see http://www.zenbi.co.uk/2011/09/04/printable-to-pdf/
 *
 * Using the wonderful iText library.  This version is built for version 2.1.7 but
 * it will work, with changes to the import statements, with iText 5.2.1
 * @author Bruno Lowagie
 * @see http://itextpdf.com/
 */

public class PDFPrinter {

   protected final FontMapper fontMapper;

   static DefaultFontMapper sDefaultFontMapper = null;
   static String sFontDirectory = "C:/windows/fonts";

   /**
    * Constructor
    * @param fontMapper if null, uses the DefaultFontMapper
   */
  
    public PDFPrinter(FontMapper fontMapper) {
      this.fontMapper = fontMapper != null ? fontMapper : getDefaultFontMapper(sFontDirectory);
    }

   /**
    * Default constructor, uses the DefaultFontMapper
    */

   public PDFPrinter() {
     this(getDefaultFontMapper(sFontDirectory));
   }

   /**
    * Change the directory for fonts. (OS dependent)
    * Generally, one should call this *before* ever instantiating a PDFPrinter
    * 
    * @param fontDirectory
    */

    public static synchronized void setFontDirectory(String fontDirectory) {
       sFontDirectory = fontDirectory;
       sDefaultFontMapper = null;  // force getDefaultFontMapper to recalculate...
   }


   private static synchronized FontMapper getDefaultFontMapper(String fontDirectory) {
      if (sDefaultFontMapper == null) {
         sDefaultFontMapper = new DefaultFontMapper();
         if (sFontDirectory != null)
            sDefaultFontMapper.insertDirectory(sFontDirectory);
       }

       return sDefaultFontMapper;

   }

   /**
    * Creates a PDF from a Pageable
    * @param pageable
    * @param os
    * @param closeStream whether to close the stream.
    *                    Since we don't create the stream, best practice is to leave this false
    * @return number of pages actually printed
    *
    * @throws IOException
    * @throws PrinterException
   */

   public int printToPdf(Pageable pageable, OutputStream os, boolean closeStream) throws IOException, PrinterException {

      // sanity check
      if (pageable.getNumberOfPages() == 0)
         return 0;

      // base page sizes on the first page
      PageFormat pageFormat = pageable.getPageFormat(0);
      float width = (float)pageFormat.getWidth();
      float height = (float)pageFormat.getHeight();
      Rectangle pageRect = new Rectangle(0.0f, 0.0f, width, height);

      Document document = new Document(pageRect);
      PdfWriter writer;

      try {
         writer = PdfWriter.getInstance(document, os);
      } catch (DocumentException e) { // don't throw as an iText exception so other classes don't need links to iText classes
         throw new RuntimeException(e);
      }

      writer.setCloseStream(closeStream);
      document.open();

      PdfContentByte contentByte = writer.getDirectContent();

      int pageIdx = 0;
      int pageStatus;

      do {

         if (pageIdx > 0)
            document.newPage();

         // The following is deprecated in iText5 but works

         Graphics2D g2d = contentByte.createGraphics(width, height, fontMapper);
        // if you are using iText5 and want to be "up to date", use
        // Graphics2D g2d = new PdfGraphics2D(contentByte,  width, height, fontMapper);

         Printable printable = pageable.getPrintable(pageIdx);
         try {
            pageStatus = printable.print(g2d, pageFormat, pageIdx);
         } finally {
            g2d.dispose();// iText in Action book says this is very important, so put in a finally clause...
         }
      }
      while ((pageStatus == Printable.PAGE_EXISTS) && (++pageIdx < pageable.getNumberOfPages()));

      document.close();
      writer.close();
      os.flush();

      return pageIdx;

   }

}

Hope this helps out some of you who wish an easy way to create PDF files from Swing components.

Note that this code as written works in iText 2.1.7, but, with just changes to the imports it also works with iText 5.2.1.  The version 5 is obviously more "up to date" but the licensing has changed.  I don't blame Bruno Lowagie for trying to make some money from his great efforts.  Here's a largely civil discussion on the matter.