Comparing Ruby to Java is comparing two languages, and on this each one has his own preferences but if you take a look at the books you pose in the picture we're not talking about Java the language, but Java all-in-all, as in frameworks. Bring your RoR, I'll bring my JavaEE and let's see what I can do that you can't and vice-versa :-)

Please people, stop harassing by talking of something you don't know nothing about :-)

Cheers,
PP