I run a server with Ubuntu 10.04 (Lucid Lynx) Minimal Server, on amd64 system. I 'd like to install the openjdk packages (jre and jdk), but when I try

sudo apt-get install openjdk-6-jdk

I get

Package openjdk-6-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 openjdk-6-jdk has no installation candidate

And I 'd like to install this package andI don't know how, while it seems to be available here