Go to the Java website, choose the JRE or JDK based on your platform and needs. Download the requisite .bin files and upload them to the serveradmin home folder. For older versions go to the Java Archives site.
Steps for JRE and JDK are both the same. Here is an example of a JDK setup,
64-bit Java is not recommended at the moment due to significant loss in performance. If 64-bit Java is used, as a convention, we recommend adding to the default folder name _64-bit. In the above example, it would be, jre1.6.0_16_64-bit.
If you try and install 32-bit Java on 64-bit Ubuntu you will get the following error,
./jdk-6u22-linux-i586.bin Unpacking... Checksumming... Extracting... ./jdk-6u22-linux-i586.bin: 113: ./install.sfx.7783: not found Failed to extract the files. Please refer to the Troubleshooting section of the Installation Instructions on the download page for more information.
This is because the ia32-libs package is missing. Using one of staff accounts,
sudo apt-get install ia32-libs # Required for 32-bit Java on 64-bit Ubuntu
Now the 32-bit Java can be installed.
su - serveradmin # If you are not already serveradmin cd ~ # Switch to the serveradmin home directory chmod +x jdk-6u22-linux-i586.bin