Transitive deps

[Sven Reimers]

"I think we are in broad agreement about how to manage build
dependencies. They are not required to be transitive -- to compile
each module we only need visibility of the modules it directly
imports."

I am sure that javac sometimes disagrees and wants to look a bit deeper
into the implementation inheritance (may be bad design/architecture, butis
valid Java)

-Sven


On Thu, Sep 5, 2013 at 2:15 PM, Neil Bartlett <njbartlett at gmail.com> wrote:

> On Thu, Sep 5, 2013 at 12:34 PM, Jaroslav Tulach
> <jaroslav.tulach at oracle.com> wrote:
> >> [...]
> > As splitted packages are rare (and maybe even unsupported in some
> versions of
> > OSGI), then a package import basically means non-transitive dependency.
> >
> > You may realize that your belief is a specialization of my general
> > observation. As such it is of no surprise, that if non-transitive JAR
> > (compilation) dependencies work sufficiently, import package works for
> you in
> > OSGi.
> >
> > Import-Package seems to be a solution of the transtivity issues, but a
> bit too
> > narrow and certainly not the only one.
> > -jt
>
>
> Stepping back a bit, I feel that the underlying failure in Maven is to
> distinguish between build and runtime dependencies. They require
> different approaches.
>
> I think we are in broad agreement about how to manage build
> dependencies. They are not required to be transitive -- to compile
> each module we only need visibility of the modules it directly
> imports. They should not use ranges because this results in
> non-repeatable builds; for my customers it is important to be able to
> reproduce a build precisely, even many years into the future. In the
> bnd build system we can go beyond fixed module identity+version and
> actually depend on the SHA hash of a module. Admittedly we also made
> the mistake of using dependency ranges at build time but now strongly
> discourage it.
>
> Runtime dependencies are unavoidably transitive. The key is therefore
> to find ways to minimise the transitive dependency graph, which is the
> purpose of the OSGi Import-Package instruction, since it creates
> opportunities to refactor module contents and/or find alternative
> providers.
>
> Neil
>
> >
> >
> >
>



-- 
Sven Reimers

* Senior Expert Software Architect
* NetBeans Dream Team Member: http://dreamteam.netbeans.org
* Community Leader  NetBeans: http://community.java.net/netbeans
                              Desktop Java:
http://community.java.net/javadesktop
* Duke's Choice Award Winner 2009
* Blog: http://nbguru.blogspot.com

* XING: https://www.xing.com/profile/Sven_Reimers8
* LinkedIn: http://www.linkedin.com/in/svenreimers

Join the NetBeans Groups:
* XING: http://www.xing.com/group-20148.82db20
* NUGM: http://haug-server.dyndns.org/display/NUGM/Home
* LinkedIn: http://www.linkedin.com/groups?gid=1860468
                   http://www.linkedin.com/groups?gid=107402
                   http://www.linkedin.com/groups?gid=1684717
* Oracle: https://mix.oracle.com/groups/18497