java for jessie

[Matthias Klose <doko@debian.org>]

At least for past releases some support of java is available on every
architecture, not only for release architectures. A big advantage is that you
don't have to use architecture specific build dependencies, but usually packages
building architecture specific binary packages just work.  That did change for
the hurd recently, but hopefully is fixable.  I would like to keep it this way,
because it makes the work for porters easier. GCJ still seems to be good enough
to build jni bindings.

Providing security updates for released versions is tedious, and not many people
are working on getting these updates into the oldstable and stable releases.
oldstable had only one openjdk version, stable unfortunately has two openjdk
versions which need updates four times a year.  For jessie there should be only
one openjdk version in the release.

Looking at the current state, this is openjdk-7, so what needs to be done, if we
want to only ship openjdk-8?

 - build openjdk-8 on the architectures that openjdk-7 builds on.
   I don't think that dropping java support on some architecture
   for the release will be an option, this affects some more
   source packages in the archive.

 - have a test rebuild with openjdk-8, preferable using the zero
   interpreter so we may catch issues on the majority of release
   architectures.

 - make sure that at least the openjdk jtreg test results look
   reasonable and we don't see any regressions between 7 and 8.
   It would be interesting to compare test TCK results for those
   who have access to this testsuite.

I would like to avoid having openjdk-8 in unstable until we have answers to
these questions. It seems to be too easy to upload packages to unstable built
using openjdk-8.

I'll be at Debconf for the java BoF, but maybe most of the issues can be
resolved even before Debconf.

  Matthias