"@throws IOException in case of a problem"

Ah yes. Now I know what's wrong.

My boss usually leaves even better description:

@returns
@throws

You guys have documentation?!

I wish I could say otherwise, but I've written "@throws SomeException If anything goes wrong." more than once in my career (but, hey, on the plus side: at least I always put the period at the end!)

Well... Makes more fun to take a deep dive in a pile of shit to figure out who has pooped...

Just a random note, since I burned myself once pretty badly....
IOException is used by many libraries for handling freeing resources on failure. Eg. closing the TCP connection.

Don't change it from IOException to something else before you've verified that. I found out that servers become very unhappy when they don't have ports left during an penetration test....