I found out a patch to build Tika against metadata-extractor 2.7. I'll stick with this version, I'm not very confident in the backward compatibility of the version 2.8.
Emmanuel Bourg __ This is the maintainer address of Debian's Java team <http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/pkg-java-maintainers>. Please use debian-j...@lists.debian.org for discussions and questions.