How to Install Java Runtime Environment (JRE) in Ubuntu 10.10 (Maverick) using PPA

Java is an object-oriented programming language developed by Sun Microsystems in the early 1990s. Java applications are compiled to bytecode, which at runtime is either interpreted or compiled to native machine code for execution.

The language itself derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities. JavaScript, a scripting language, shares a similar name and has similar syntax, but is not directly related to Java.
Install java in ubuntu 10.10
Open the terminal and run the following commands

sudo add-apt-repository ppa:sun-java-community-team/sun-java6
sudo apt-get update
sudo apt-get install sun-java6

Ubuntu 10.04(Lucid) users also can install java using this PPA

nb:Sourcecode here