Monday, November 2, 2009

Porting a CFPDF / CFPDFFORM-Dependent Application to Open BlueDragon

In my continuing war against all things PDF in ColdFusion, today I believe I have achieved victory.

If you've been following my posts (OK, rants) over the past few weeks you'll know that I ran into some annoying bugs in CFPDFFORM that were wreaking all sorts of havoc with the one application I wrote that depends on CFPDFFORM for a key part of what it does. I sent my test case to Adobe Support and, well, there are probably a million ways to couch this nicely, but the bottom line is they told me they can't/won't fix the bug, and their suggested workaround was to use iText to populate my PDF forms instead of using CFPDFFORM. Given that I ran into another annoying bug with CFPDFFORM a couple of years ago and got another "can't/won't fix" answer, this was strike two for CFPDFFORM. And personally I don't like being backed into a corner by a third strike before making a change.

Now that my CFPDFFORM code had been changed over to use iText instead (which gave some nice speed benefits as well), the only remaining thing keeping me tied to ColdFusion 8 was the use of CFPDF to merge multiple PDFs into a single file. I looked into doing this with iText and although it's doable, even being the gearhead I am I have to admit that's a bit of a hassle. So before implementing that solution I decided to hunt around a bit more.

Enter Apache PDFBox.

PDFBox is already bundled with Open BlueDragon since we use it as the underlying libraries for some CFDOCUMENT functionality, but it's a version behind the absolute latest. Turns out that the newest version of PDFBox has a great, easy-to-use PDFMergeUtility built in. This made removing my dependence on CFPDF (which isn't in Open BlueDragon yet) pretty simple.

My application populates a varying number of individual PDF pages and then merges these pages into a single PDF file at the end of processing. So I use an "assembly" directory to build up the individual pages of the final result, and the final step is to merge the files. Previously I was using CFPDF for this:

<cfpdf action="merge"
       overwrite="true" />

And the PDFBox PDFMergeUtility solution looks like this:

<cfset pdfMerger = CreateObject("java", "org.apache.pdfbox.util.PDFMergerUtility").init() />

<cfloop list="#filesToMerge#" index="fileToMerge">
  <cfset pdfMerger.addSource(fileToMerge) />

<cfset pdfMerger.setDestinationFilename("#destDir##destFileName#.pdf") />
<cfset pdfMerger.mergeDocuments() />

So it's a few more lines of code, but honestly not bad at all compared to the CFPDF version, and if you've been looking for ways to do some of what CFPDF and CFPDFFORM do in CF 8, between iText and PDFBox it looks like you're covered.

I was forced to make the switch from CFPDFFORM to iText in order to get around a bug in CFPDFFORM, and with that out of the way it was only one more step to make this application CFML engine agnostic. I need to do some additional testing but with the CF 8 dependencies removed the app is running great on Open BlueDragon. I'll do some comparison metrics but in initial testing, particularly since this is a CFC-heavy application, the speed and CPU load are both dramatically improved. Speed is about 30-50% faster (which makes a BIG difference when this app runs processing for hours at a time), CPU utilization is about half (CF completely pegs the CPU while this app is in full processing mode), and it's noticeably lighter on RAM as well. All told the minor hassle of reworking these portions of the app will have been well worth it.

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