Thanks for taking your time to report this issue and help making Ubuntu better.
I stumbled across this issue after I had reported a similar one. (Bug 1406483 where I triggered it by installing maven and openjdk-8-jdk)
I was able to reproduce this issue when installing openjdk-8-jre-headless on Ubuntu 14.10, though when I tried on Ubuntu Vivid it added the certificates and worked fine. Tough I don't see why it would as neither openjdk-8 nor the ca-certificates-java package has changed between these two releases.
(Oh, and I also found bug 983302 where it looks like the same issue has plagued the headless package for openjdk-7)
Thanks for taking your time to report this issue and help making Ubuntu better.
I stumbled across this issue after I had reported a similar one. (Bug 1406483 where I triggered it by installing maven and openjdk-8-jdk)
I was able to reproduce this issue when installing openjdk- 8-jre-headless on Ubuntu 14.10, though when I tried on Ubuntu Vivid it added the certificates and worked fine. Tough I don't see why it would as neither openjdk-8 nor the ca-certificates -java package has changed between these two releases.
(Oh, and I also found bug 983302 where it looks like the same issue has plagued the headless package for openjdk-7)