Rules for overloading methods using widening, boxing, and var-args : Boxing Unboxing « Utility Classes « SCJP

1. SCJP
2. Utility Classes
3. Boxing Unboxing

Primitive widening uses the "smallest" method argument possible.

Used individually, boxing and var-args are compatible with overloading.

You CANNOT widen from one wrapper type to another. (IS-A fails.)

You CANNOT widen and then box. (An int can't become a Long.)

You can box and then widen. (An int can become an Object, via Integer.)

You can combine var-args with either widening or boxing.