problem with sun-java6-jdk

[SchrodingerCat]

Hi all,
i am trying to install Bluej on ubuntu 12.04. In the website i found out that first at all i have to install the sun-java6-jdk but
after my input

sudo apt-get install sun-java6-jdk

this is the output

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package sun-java6-jdk is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'sun-java6-jdk' has no installation candidate

how can i solve the problem?
thank you

[Cheesemill]

The official Java isn't allowed in the repositories any more ever since Oracle changed the licensing terms. There are 2 options available to you, either install Open JDK from the repositories or follow the steps here to install Oracle Java.

All of this information can be found on the Ubuntu Java wiki page:
https://help.ubuntu.com/community/Java

[pkadeel]

Oracle's original java jdk can not be installed via repository.

What you can do via repository is to use openjdk. It works in most of the cases.
Version 7 (latest)

sudo apt-get install openjdk-7-jdk

Version 6

sudo apt-get install openjdk-6-jdk

If you must use the original Oracle's JDK then use the link given in cheesemill's post.