I am running Ubuntu 11.04 and was trying to install the Java OpenJDK 6.0 (and 7.0) on my system but I received the following error:
Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
I tried installing several different Java packages but all of them failed with the same error. Finally, I arrived at a working solution by running the following commands:
sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner"
sudo apt-get update
Now you can successfully install Java on your system!
sudo apt-get install openjdk-6-jre-headless -y