Would it be possible to do this as a type-alias type thing that disapears at compile time? As far as I am aware, Java has no support for such type aliasing, but it should be possible to add a pre-compiler phase to your build process that replaces these types with what they are aliases of. The only part of this that seems complicated is the type checker, which would need to be aware of the difference between AccountId and long.
I could see it being done with annotations + processing them perhaps, as some frameworks do for database properties such as index/uniqueness. An object for every scalar datatype is just overkill, even if it solves a legitimate problem.
