Why is it allowed to have several modules with the same name?

[Gunnar Morling]

Why is this situation not considered an error though? Relying on ordering
on the module path seems to go against one of the core promises of the
module system: reliability and less "surprises".

--Gunnar


Am Sa., 26. Dez. 2020 um 17:27 Uhr schrieb Jonathan Gibbons <
jonathan.gibbons at oracle.com>:

> If the two modules with the same name are in different positions on the
> module path, the first one will be seen and will completely hide any
> subsequent occurrences of modules with the same name.
>
> If two modules with the same name are found in the same directory on the
> module path, such as in differently-named jar files, then that is an
> error, because neither can be said to have precedence and hide the other.
>
> -- Jon
>
> On 12/26/20 3:29 AM, Gunnar Morling wrote:
> > Hi,
> >
> > So far it was my assumption that the module system would reject
> > multiple modules with the same name to be present.
> >
> > But this seems not to be the case; if I have two versions of a module JAR
> > on my module path -- i.e. two modules which have the same module name and
> > export the same set of packages -- the java command does not complain
> (nor
> > does javac or jlink). Is this an expected behavior?
> >
> > Thanks,
> >
> > --Gunnar
>