Updating Ubuntu (10.04 and up) to use Sun Java

I am in the middle of a home project to build a virtual environment using Proxmox and running into Java issues. Since Proxmox uses java as a VNC console it is necessary to use the correct version (of Java) to access VM’s.  By using the wrong version you can cause instability issues and thus bad things to happen.

This is not just a problem with Proxmox either, there are a few other programs and apps that behave poorly with this version of Java, notably for me, Minecraft. Apparently newer versions of Ubuntu have shipped with the OpenJDK version as their default version and in this post I will discuss how to use to the Sun Java 6 version.

Switch to the appropriate directory, in my case I used my home directory and either punch these commands in or copy/past them to get get Ubuntu to see the correct repos.

cd ~/
wget https://raw.github.com/flexiondotorg/oab-java6/master/oab-java6.sh -O oab-java6.sh
chmod +x oab-java6.sh
sudo ./oab-java6.sh

Once this script goes through and does its thing you should have access to the old sun-java6 repos.  So to install the correct pieces for Proxmox use apt-get to install the appropriate packages.

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

To set system settings to prefer Sun Java over the OpenJDK version type the following commands:

sudo update-alternatives --set java /usr/lib/jvm/java-6-sun/jre/bin/java
sudo update-alternatives --set javaws /usr/lib/jvm/java-6-sun/jre/bin/javaws
sudo update-alternatives --set mozilla-javaplugin.so /usr/lib/jvm/java-6-sun/jre/lib/*/libnpjp2.so

Now you should have a much more stable experience using Proxmox and the console to take a look at your VM’s!  I can’t take the credit for this but I can ease the burden for anybody that comes across this post.


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Josh Reichardt

Josh is the creator of this blog, a system administrator and a contributor to other technology communities such as /r/sysadmin and Ops School. You can also find him on Twitter and Facebook.