SCJP question: Java method overloading with var-args. What is the rationale?

Answer 1

You are right that widening comes before boxing, which in turn comes before var-args.

But you seem to be treating the first method as callMethod(Integer i), not callMethod(Integer... i). Since both methods use var-args, there's a priority tie. That is, neither one meets the criteria for boxing alone, but both meet the criteria for var-args.

Remember that it's illegal to widen, then box (although I did some research before posting this answer and found that it IS legal to box, then widen). Similarly, you won't get box, then var-args behavior; the compiler skips right to the var-args step and sees two methods that take var-args.

EDIT: I should clarify that you WILL get box-then-var-args behavior if there's no ambiguity. In other words, if there was only one callMethod(), and it took Integer... i, you would get "Wrapper."