language design - Why doesn't Java support unsigned ints?

Question

Why doesn't Java include support for unsigned integers?

It seems to me to be an odd omission, given that they allow one to write code that is less likely to produce overflows on unexpectedly large input.

Furthermore, using unsigned integers can be a form of self-documentation, since they indicate that the value which the unsigned int was intended to hold is never supposed to be negative.

Lastly, in some cases, unsigned integers can be more efficient for certain operations, such as division.

What's the downside to including these?

Answer 1

This is from an interview with Gosling and others, about simplicity:

Gosling: For me as a language designer, which I don't really count myself as these days, what "simple" really ended up meaning was could I expect J. Random Developer to hold the spec in his head. That definition says that, for instance, Java isn't -- and in fact a lot of these languages end up with a lot of corner cases, things that nobody really understands. Quiz any C developer about unsigned, and pretty soon you discover that almost no C developers actually understand what goes on with unsigned, what unsigned arithmetic is. Things like that made C complex. The language part of Java is, I think, pretty simple. The libraries you have to look up.