Java is FOSS.

Oracle used excuse, that it's current OpenJDK license (GPLv2) is incompatible with license, used by Google's runtime (Apache 2). If Google re-licensed it's Java implementation under GPL, some of arguments, used by Oracle lawyers (code reuse and patent (?) violations), would have been void, and arguing about reuse of APIs would have been a lot harder.

Of course, this does not really matter, because the whole lawsuit is just excuse for power games between corporations. Oracle's goal wasn't about Java licensing, it was about gaining some degree of control over emerging Android ecosystem.