JFreeChart runs free!

Post by **david.gilbert** » Wed Dec 14, 2005 12:36 pm

One of my goals for JFreeChart is that it should be possible to run it on an entirely free software stack. That is, you should not need to use any proprietary software---this includes Sun's JDK under its present licensing terms---to use JFreeChart. That goal is close to being realised, as it is now possible to run JFreeChart using GNU Classpath-based runtimes and the Cairo vector graphics library. See this link for details:

http://www.object-refinery.com/jfreechart/free.html

Cairo is scheduled to be better integrated into GNU Classpath in the coming months, so in 2006 you can expect the setup steps outlined in the link above to become a lot simpler - it should "just work". All in all, I think this shows the excellent progress being made by the GNU Classpath developers.

mhilpert · Post by **mhilpert** » Wed Jan 11, 2006 5:16 pm

You always talk about GNU classpath, but this is just a "free" version of the core libraries. You can't run Java applications with this. You still need a virtual machine. So, if you stress GNU classpath as the libs to use, what "free" JVM is JFreeChart selecting for a "total free" system?

Post by **david.gilbert** » Wed Jan 11, 2006 5:36 pm

I use JamVM, mainly because it is relatively easy to set-up and get working with GNU Classpath CVS (as well as the snapshot releases):

http://jamvm.sourceforge.net/

There are other free VMs around (e.g. Kaffe, GIJ, JikesRVM, SableVM, CACAO). I haven't tried it, but I'm sure I read on the Classpath mailing list that someone else got StatCVS (which uses JFreeChart) running on CACAO (there's no fundamental reason why it won't work with any of the others, I just haven't tried them):

http://www.cacaojvm.org/

Right now, making JFreeChart work with GNU Classpath-based runtimes requires some configuration work to install "bleeding edge" versions of a couple of dependencies. It's not very user-friendly. Among other things, I hope my presentation will inspire other GNU Classpath hackers to help smooth the rough edges, so that by the end of 2006, the following should work on any relatively up-to-date Linux installation:

Code: Select all

$> jamvm -jar jfreechart-1.0.x-demo.jar

The free runtimes are not 100% ready for end-user consumption yet, but they sure are improving fast.

eriktamu · Post by **eriktamu** » Wed Jan 18, 2006 5:14 pm

Forgive my ignorance on this subject but would this mean that the supplied jar would not be using Sun's JDK when built. If I wanted to use Sun's JDK, would I have to manually build it?

Post by **Taqua** » Wed Jan 18, 2006 5:34 pm

Hi,

no, the format of the jar files and the class file format is strictly defined by the Java Standard. A jar or *.class file created with one JDK must run on all other JDKs as well, no matter who implemented that runtime environment.

So it only means: You now have the choice to use the Jars on free (as in free speach) JVMs as well. No recompile is needed.

Regards,
Thomas