Go to the Java website, choose the 64-bit JRE (Java Runtime Engine). Download the .tar.gz file and upload the file to the serveradmin home folder. For older versions of Java go to the Java Archives site.
Originally, I had endorsed using 32-bit Java on 64-bit Ubuntu. Though I have not had a chance to do performance testing, with Cloud computing and lack of documention on 32-bit Java, it's time to move to 64-bit Java.
Use the account that will be launching the Java process. In this example it will be serveradmin,
su - serveradmin # If you are not already serveradmin cd ~ wget http://download.oracle.com/otn/java/jdk/7u7-b10/jre-7u7-linux-x64.tar.gz
The steps for JRE and JDK are both the same. Here is an example of a JRE setup,
su - serveradmin # If you are not already serveradmin cd ~ # Switch to the serveradmin home directory tar -xvpf jre-7u7-linux-x64.tar.gz
The result will be an uncompressed jre directory using the same name as the package. In this example the folder name would be, jre-7u7-linux-x64.
If you plan to use multiple versions of Java, we recommend keeping the folder name with the version number information and using symbolic links. If you are only using one version of Java, then simply rename the folder.
For the server example, we will rename the folder,
mv jre-7u7-linux-x64 java
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