Debugging Java

On the JVM, start with options:

'-Xdebug -Xrunjdwp:transport=dt_socket,address=41422,server=y,suspend=n'

and then use jdb to connect to the port 41422.

Installing JDK 1.5 on Ubuntu

First download JDK from Sun site (also requires filling up a form). Then follow the steps at:

http://www.debian-administration.org/article/Installing_Sun%27s_Java_environment_on_Debian_systems

In particular one important step is running:

fakeroot make-jpkg jre-1_5_0_03-linux-i586.bin

Using Multiple Java versions

For building Katta, I needed to use Java 6 (compilation did not work with Java 1.5). Now I have two java versions installed on my dev laptop. To make use of Java 6, I just needed to set JAVA_HOME and PATH appropriately (export PATH=$JAVA_HOME/bin:$PATH) and then the compilation worked fine.