Ubuntu 10.04, by default, installs the open source version of Java OpenJDK. However many users would want to switch to the standard version of Java from Sun. So, these are the following steps to install Sun Java for Ubuntu:
Go to System>Administration>Software Sources and add the following repository:
deb http://archive.canonical.com/ lucid partner
(If you're unsure about how to add repositories, take a look here for a detailed explanation with screenshots: http://explore-ubuntu.blogspot.com/2010/04/adding-repositories.html)
Finally go to Accessories>Terminal and type the following:
sudo apt-get update
And the following to finish the installation:
sudo apt-get install sun-java6-jre sun-java6-plugin sun-java6-fonts
