> On Feb 12, 2022, at 10:16 PM, Srikanth Adayapalam
> <srikanth.adayapa...@oracle.com> wrote:
>
> I understand Frederic is asking about whether the spec​ inadvertently allows
> something it should not - Here anyway is javac behavior:
>
> Given:
>
> abstract class A implements ValueObject {
> int x;
> }
>
> on compile:
> X.java:1: error: The type A attempts to implement the mutually incompatible
> interfaces ValueObject and IdentityObject
> abstract class A implements ValueObject {
> ^
> 1 error
Yep, this is expected and consistent: javac sees the field and infers the
superinterface IdentityObject (per the language rules), then detects the
conflict between interfaces.
A slightly more interesting variation: declare a simple interface Foo; change
to 'A implements Foo'. This compiles fine, inferring A implements
IdentityObject. Then separately compile Foo so that it extends ValueObject. No
compilation error, but the JVM should detect the IdentityObject/ValueObject
conflict when A is loaded.
To generate the kind of class files Fred asked about, you'd need to use
something other than javac.
