In Ubuntu 11 it’s really easy to install Sun’s version of Java JDK (or JRE). Why would you want to do this?  Well, personally, I have found that the OpenJDK doesn’t always work quite exactly right with a lot of Java programs, so I prefer to use the Sun JDK (I guess it’s Oracle now).

To install simply do the following from your console:

sudo add-apt-repository ppa:ferramroberto/java
sudo apt-get update
sudo apt-get install sun-java6-jdk sun-java6-jre
sudo update-alternatives --config java

Then you’ll want to pick the Sun version of Java.  Now you’ll be using Sun Java whenever you execute the ‘java’ command.  You can also verify this by typing ‘java –version’ and you should see the HotSpot mentioned, instead of the IcedTea.