According to https://wiki.archlinux.org/index.php/Java I can install Open JDK 7 on a clean Arch Linux installation by invoking the command
pacman -S jdk7-openjdk
But when doing so, I get an error saying
error: target not found: jdk7-openjdk
I already commented out my nearest Pacman repository in /etc/pacman.d/mirrorlist
and ran a first update by invoking pacman -Syu hoping that this would cause the package above to be discovered.
How can I install Open JDK 7 on Arch Linux using pacman?
Edit: I'm running a Raspberry Pi with an ARM processor and I'm hoping to get a Java build that is tailored for its hardware and uses the OS hardware floating point support.
Get the best mirror near you (check this list); you can even generate a new mirror list on the archlinux website.
Then run # pacman -Syy; # pacman -Su; # pacman -S jdk8-openjdk
(or jre8-openjdk
if you only need the JRE)