I do not think universities should give students skills "coding in OOP paradigm using Java", it's more like confidence in mastering any field, kind of a meta-skill needed by serious programmer, junior or otherwise. And as higher education provides a lot of diverse courses, wise students learn how to learn.

As for confidence, it can come with some hands-on work, eg participating in serious open source projects, which do have high quality standards. Confidence also comes for instance from competitions, conferences, own business, and even from previous job interviews. I am talking about fresh degree holders.

And I also mean genuine confidence, which is really rooted in one's abilities, not the confidence to hypnotize the interviewer.

But to be honest, I do not know myself how to recognize a junior with good potential.