Is that the modern Java equivalent of the single-method interface in Go? I can see its an abstract class - what do you do if you want to implement both Reader and Writer?
However, there's lots of code which just takes a Reader/Writer and then you're SOL.
(In general, the I/O interface/class hierarchy in Java is a bit of a mess because a lot of it was retrofitted to maintain binary compatibility. The equivalent stuff in Guava seems a bit saner, but of course not directly usable with all the 3rd party libraries you might want -- it has shims for the most part, though.)
