[BiO BB] Ensembl and Gene Ontology terms

[Paco B C]

Hi!
this is my first message in this list. My name is Paco and I'm doing my PhD.
on Bioinformatics in University of Leuven, Belgium.
I would like to build a java module that, given a list of Ensembl Gene
Identifiers, it would give back their related Gene Ontology terms. I've
accessed the GO database, but I can't find ENSG terms and I've read in the
Ensembl website that they give the link to external databases for
translation and transcript objects but not for genes (maybe in the future,
but not now).
My question is, do you know which database could I query in order to get
this relation within Ensembl and GO terms?
Thanks!
Paco