this is not a defect, changed to rfe p3.

ok, let it be enhancement, but it affects big area and should be at least P2

Why not just use a datatype.  Datatypes are not generated during code generation.

Hi Trey, there was a discussion between us about "interface datatypes" before,
see some reasons:
1) I didn't get clearly difference between datatypes and classes from uml2.0
spec but datatypes are more simple classifiers then classes and looks good for
int and may not looks good for JFrame for example.
2) I may want to see members of library classes on diagram (I can't see members
for daatypes)
3) there is no way to use datatypes as interfaces (for examp-le Runnable)
4) classes are used in patterns

> 1) I didn't get clearly difference between datatypes and classes from uml2.0
> spec but datatypes are more simple classifiers then classes and looks good for
> int and may not looks good for JFrame for example.
A datatype is the best way to specify classifiers that are not included in our system.

> 2) I may want to see members of library classes on diagram (I can't see members
> for daatypes)
A datatype is a classifier, and as such can own operations and attributes.  We could have the tree show 
the operations and attributes.

> 3) there is no way to use datatypes as interfaces (for examp-le Runnable)
This is a good example.

> 4) classes are used in patterns
Actually Class Roles are using in design patterns, not classes.  Class Role elements and Class elements 
are not the same thing.  They just look the same.

1) may be
2) but hard to work from diagram area, and aren't shown on diagram, in my
opinions users most interested in diagram view rather then in model tree.
4) just apply any EJB2.0 pattern and you'll get a lot of java.*,javax.* classes
and interfaces which shouldn't participate in code generation (see issue 90189)