Install and setup the Java development kit.
This adds JAVA_HOME to the global environment, by sourcing the jdk's setup-hook on shell init. It is equivalent to starting a shell through 'nix-shell -p jdk', or roughly the following system-wide configuration: environment.variables.JAVA_HOME = ${pkgs.jdk.home}/lib/openjdk; environment.systemPackages = [ pkgs.jdk ];