I've started to learn #Java over the past few days. Not the first time I've looked at it, but now my #Python is more advanced I'm finding Java makes more sense to me. Perhaps I'll reach the point of becoming vaguely useful in a while!
As far as IDEs are concerned, #Jetbrains is the obvious one, not just because I use #PyCharm Pro, though familiarity certainly helps. But I've decided to try out #eclipse properly (used in the past with #PyDev which I did not get on with) and also #Netbeans.