I want to downgrade from OpenJDK Update 25 to OpenJDK Update 21.
If I look, for example, at security.ubuntu.com or at mirror.pnl.gov, I can see that .deb files for Update 21 are still there, however, when I use apt-cache show or aptitude, I only see Update 25 and Update 3, and if I try:
aptitude -s install openjdk-7-jre-headless=7u21-2.3.9-0ubuntu0.12.04.1
Unable to find a version "7u21-2.3.9-0ubuntu0.12.04.1" for the package "openjdk-7-jre-headless"
Is there any way I can downgrade using apt tools? If the only option is dpkg, will this package be "visible" for aptitude, for example, when resolving dependencies?