Mittwoch, 22. August 2007

Java 1.3 on Ubuntu

As we (still) provide Java 1.3 binaries for Apache FOP (for rumored AIX users who are still stuck there ;-) I was going to need a JDK 1.3 for my Ubuntu (Edgy Edge) system to do some testing.

So I went to Blackdown (remember that Sun didn't provide Java for Linux in the early days...) and downloaded the "latest" JDK 1.3, which is Java2 SDK 1.3.1-02b-FCS.

After the installation it threw the following error on the first run:
/home/chrisg/j2sdk1.3.1/bin/i386/native_threads/java: relocation error:
/home/chrisg/j2sdk1.3.1/jre/lib/i386/ symbol __libc_waitpid,
version GLIBC_2.0 not defined in file with link time reference
Some googling turned up that SUN used a private interface from glibc. Well, no easy fix for this...

A closer look at lead to the Java Download Archive (albeit Sun makes it bit hard to find) where I found J2SE 1.3.1.
After the installation the following commands are needed:
sudo apt-get install libstdc++6
sudo ln -s /usr/lib/ /usr/lib/
and then you should have a working JDK1.3.

The testing (of FOP) revealed some strange errors but that's another story...

Freitag, 17. August 2007

JUG-KA - Java User Group Karlsruhe

Via Xing I discovered a meeting of the Java User Group Karlsruhe which took place yesterday at the Universität Karlsruhe. The JUG-KA is quite young actually - it was just the second meeting held ever. As it's just a 10 minute drive I decided to attend it (and it was quite a strange feeling to sit in a lecture room at my old University ;-)

There were about 50 people attending and the first presentation was an overview of the Spring Framework held by Oliver Schlicht from Synyx. The second presentation was done by Dr. Stefan Schneider from SUN and was about Java Hotspot VM garbage collection and memory pool sizing techniques, including demos with visualgc and JCconsole. The bottom line was that with Java 6 the VM settings are good enough most of the time and the only thing left to configure is the maximum heap size. Nevertheless it's a good idea for every developer to have a look a the memory usage of an application with the mentioned tools.

The next meeting is scheduled for sometime in October (IIRC one topic will be again Spring), but I think it would be nice to also have a more informal Stammtisch.