The big secret revealed! A PDF viewing library!

Last week I told you we had a secret new open source project to release. Think of it as an early Christmas present. A project that you've never heard of and has nothing to do with JavaFX (which is partially untrue, but I'll get to that in a second). Well, it's almost the end of the week so here is the secret. You can listen to MP3 announcement (played on stage at the JavaPosse's JavaPolis session), or simply read on. We are releasing an

Open Source 100% Java PDF Renderer/Viewer

That's right, a 100% Java library which can parse PDF files and draw them to the screen. It's (creatively) named the SwingLabs PDF Renderer, and hosted at It's the same license as the rest of SwingLabs (LGPL) so you can easily embed it in your own applications. Several of us inside the desktop Java team here at Sun have been working hard on getting this released and now it's finally here. Go check it out at

So, you probably have a few questions. First of all:

Why should I care?

You should care because PDF is one of the formats that makes the web go 'round. Soon to be an ISO spec, PDF is the standard way of exchanging non-interactive documents on the web. Everything from tax forms to clip art can be stored in PDFs. Mac OSX makes heavy use of PDF both as an asset format (the many widget images found in Aqua) and also as an ideal archive format using AppleScript workflows. PDF is everywhere.

Once a PDF is created you know with great certainty that it will display and print exactly as you want on any platform. Hmm. Write a PDF once and run it anywhere? Sounds like a good fit for Java! Combined with PDF writing libraries (like iText), you can do pretty much anything you want with PDFs.

What can I do with it?

Anything you want! You can embed a PDF in your Swing app, draw on top of it, and even render to places other than the screen (like PNG images). The awesome guys over at Project Wonderland have even started experimenting with projecting PDFs into their 3D shared universe. Most importantly, we know you'll come up with things we never thought of. That's why we are open sourcing it.

Experimental Project Wonderland support

As another bonus, we plan to use this library to build a PDF imported for the designer tool that I'm working on. So, technically, this does have something to do with JavaFX, but that's not the focus. The focus is general PDF support for Java.

Where did it come from and Who is running it?

The SwingLabs PDF Renderer was originally written in 2003 by researchers at Sun Labs for an internal collaboration tool called Sun(TM) Labs Meeting Suite. It was originally targeted at output from OpenOffice, so you will find it can support most OpenOffice PDF exports.

While the original code drop is from Sun, we want to get the community heavily involved. To make sure that happens we have recruited Tom Oke from Elluminate to run the project. He will act as project owner and lead architect. He is rapidly becoming an expert in the code and looks forward to discussing features with other contributors. And speaking of other contributors..

What about iText and JPedal?

JPedal uses the GPL license, making it non-viable for certain applications. We think that the LGPL is a better fit for a library like this. iText is not a viewer/renderer. iText generates PDFs, it doesn't view them. This makes iText and the SwingLabs PDF Renderer great partners. I look forward to seeing how people combine them.

What are the limitations and how can I help?

As I said, we originally targeted OpenOffice exports, so a few things are missing. It implements most of the PDF 1.4 spec but is missing transparency, fill-in forms, and certain font-encodings. We hope that interested developers in the community will help us fill in these missing features.

If you want to get started then head over to the PDF-Renderer project website, download the code, and join the mailing lists.

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Posted December 13th, 2007