jmod usage info, and suggestions

[Mark Reinhold]

> Date: Thu, 10 Dec 2009 13:24:33 -0800
> From: jonathan.gibbons at sun.com

> Here's jmod's usage output:
> 
>> usage: jmod config [<module-id> ...]
>>        jmod create [-L <library>] [-P <parent>]
>>        jmod dump <module-id> <class-name>
>>        jmod identify
>>        jmod install <classes-dir> [-r <resource-dir>] <module-name> ...
>>        jmod list [-v] [-p] [<module-id-query>]
>>        jmod preinstall <classes-dir> <dst-dir> <module-name> ...
>>        jmod reindex [<module-id> ...]
>>        jmod show <module-id>
> 
> Note, in particular, it uses <classes-dir> in a couple of places. It is not
> clear from the context whether this is a "typical" classes directory
> (e.g. build/classes) containing a single module, or a new "modules" directory,
> with an extra level of naming before getting to the package hierarchies.  Going
> forward, there is the potential for an ongoing source of confusion here, so we
> should try and come up with terminology to distinguish these cases, and we
> should then be careful to use it consistently.

Agreed.  I'll make a note to fix this.

> I believe the current version of jmod expects <classes-dir> to be a modules
> directory.

No, not quite ...

> A common case may be for folk to compile their code as a single module, so they
> will likely compile to build/classes, not build/modules.  Maybe jmod could
> detect this, by checking for <classes-dir>/module-info.class or
> <classes-dir>/*/module-info.class.

That's what it already does.

- Mark