Internship for a Java Role

Depending on your situation, some pay might be preferable to none. However there are definitely companies out there that pay "normal" wages to interns. In teams I've worked on interns were typically paid <€2k per month, which I would've said was very low, but the interns themselves disagreed with me as they had friends/classmates in other companies getting paid nothing.

(note: as I mentioned in another comment, it's illegal in Europe to pay interns nothing, but this law is widely flaunted and enforcement is non-existent)

One thing to consider is progression & promotions: expect to change company: if you're hired on the back of an internship will likely net you similarly low wages, which may make %-based pay-rises tricky if you stay in the same company.

Depending on which country it's ok, just don't continue for more than 2, max 3 months. Actively look for dev positions and also tell the company you would like to upgrade to a full time dev position after maximum 3 months if they're happy with your performance.

I'm not sure what software dev internships generally pay... But that seems incredibly low even for europe. Maybe other interns can weigh in.

I mean, in France if you're over 2 months of internship the minimum is 3.90€ per hour If you're doing 35h per week you should be at the double (540)

So it really depends on the country the company is based on. Try to look for the legally minimum for internship there

When I did my internship in 2000, they paid me 1000 euro/m for doing web dev stuff on the Microsoft stack. This was in the Netherlands, and I'm Dutch, so maybe not the same situation.

Many EU internships would pay the pro-rated same as a new graduate; so 200-300/month seems crazy. Here in Switzerland I think you'd expect to get around 3.5-4k per month

Yes, it is good offer.

Most internships are not paid and getting experience is more valuable than those 200 - 300 euros.

But don't stay intern too long.