dev-java/jdbc2-stdext-2.0-r2 in java-overlay has LICENSE="sun-bcla-jdbc2", but that license does not exist. A license file must be added to java-overlay/licenses/ or the LICENSE setting changed in dev-java/jdbc2-stdext/jdbc2-stdext-2.0-r2.ebuild (or both).
More likely the license was removed from main tree as he couldn't find a user of it. Oracle now offers the download under Oracle-BCLA-JavaSE which is still in tree. Fixed, thanks for the report. *jdbc2-stdext-2.0-r3 (13 Jan 2013) 13 Jan 2013; Ralph Sennhauser <sera@gentoo.org> -jdbc2-stdext-2.0-r2.ebuild, +jdbc2-stdext-2.0-r3.ebuild: sun2oracle - hompage, url, license, thanks to Victor Orozco <tuxtor@shekalug.org>. #450918 #294406