install different version Java in Ubuntu

I want to install Java1.5 and Java 1.6 on my Ubuntu 8.10. And that's he propose in this topic.

1. update or reload Syn Package Manager

Java 5
The Java 5 packages available is listed as follows:

sun-java5-bin	sun-java5-fonts	sun-java5-plugin
sun-java5-demo	sun-java5-jdk	sun-java5-source
sun-java5-doc	sun-java5-jre	sun-java5-src

Java 6
The Java 6 packages available is listed as follows:

sun-java6-bin	sun-java6-javadb	sun-java6-plugin
sun-java6-demo	sun-java6-jdk	sun-java6-source
sun-java6-doc	sun-java6-jre	sun-java6-src
sun-java6-fonts	sun-java6-jre-headless

2. install different version Java
So you can install them from Syn Package Manager or commend line as:

sudo apt-get install sun-java6-jre sun-java6-jdk sun-java6-plugin

3. verify Java installation

java -version

4. list all the available Java runtime environments

update-java-alternatives -l

5. change default java version in Ubuntu

sudo update-java-alternatives -s <JRE Version>

6. setup JAVA_HOME and PATH
 setup for all user or Ubuntu in /etc/environment:

JAVA_HOME=/usr/lib/jvm/java-6-sun/

 add /usr/lib/jvm/java-6-sun/bin in the PATH

for my home ~/.bashrc

JAVA_HOME=/usr/lib/jvm/java-1.5.0-sun/
export JAVA_HOME
PATH=${PATH}:$JAVA_HOME/bin

all done.