install jdk5 in ubuntu 9.10

How install jdk5 in ubuntu 9.10(Copy from)
use the Ubuntu 9.04 repositories to get Java5
This method adds the Jaunty repositories and installs Java5 as the default java setting in the system. Open the sources file (/etc/apt/sources.list) for editing, as root

  $ sudo gedit /etc/apt/sources.list

and add:

  deb jaunty multiverse
  deb jaunty-updates multiverse

save the file and close gedit. Next sync your sources by running

  $ sudo apt-get update

and install

  $ sudo apt-get install sun-java5-jdk

To set the system to use Java 5 you need to update your java alternatives by running

  $ sudo update-alternatives --config java

Choose java-1.5.0-sun and you should be done.

Hopefully the Android Open Source Project will build with Java 6 shortly but the above solutions should get you going with platform work on Ubuntu 9.10.