Java 8 introduced many new feature that support a more functional programming style.
These features allow Java programmers to write code that looks more like code in Ruby, Scheme, LISP, and certain other languages.
Check out these links:
Not everyone is fully on the bandwagon with the new functional programming style. And that’s probably a good thing. We want to make sure to avoid treating every problem as a nail just because we have a shiny new hammer.
Read these too, and form your own opinions—but don’t hold onto those opinions too tightly. Take everything you read seriously, but not literally.