I just noticed the same on amd64. After the oneiric->precise upgrade, I'm left with
/etc/alternatives/javac -> /usr/lib/jvm/java-6-openjdk/bin/javac
but the binary is in /usr/lib/jvm/java-6-openjdk-amd64/bin/javac
I purged and reinstalled openjdk-6-jdk, the alternatives are correct now. So this needs fixing on upgrade.
I just noticed the same on amd64. After the oneiric->precise upgrade, I'm left with
/etc/ alternatives/ javac -> /usr/lib/ jvm/java- 6-openjdk/ bin/javac
but the binary is in /usr/lib/ jvm/java- 6-openjdk- amd64/bin/ javac
I purged and reinstalled openjdk-6-jdk, the alternatives are correct now. So this needs fixing on upgrade.