JAI is currently only available as a binary and wants to install into an already existing java installation. This ebuild installs the JAI files into the system's chosen JDK. I've only tested it on blackdown's jdk, where it seems to be working fine.
Created attachment 20641 [details] Ebuild
What a blessing. I've been trying to figure out how to get this installed. However, a problem exists with this: paul root # emerge jai Calculating dependencies ...done! >>> emerge (1 of 1) dev-java/jai-1.1.2 to / >>> Unpacking source... tail: cannot open `+240' for reading: No such file or directory !!! ERROR: dev-java/jai-1.1.2 failed. !!! Function src_unpack, Line 21, Exitcode 1 !!! (no error message)
Fixed to install under any JDK.