Question about FileManagers in Jigsaw.

[Jonathan Gibbons]

On 03/12/2012 09:08 AM, Fredrik Öhrström wrote:
> 2012-03-12 16:22, Jonathan Gibbons skrev:
>> Note that even in single module module, the "single" refers to the
>> sources being compiled.
>> Even in single module mode, you can refer to other modules which have
>> already been compiled
>> are are available on either the module path or in a module library.
>>
>> If you need to compile the sources for multiple modules in the same
>> compilation, then you must
>> use multiple module mode, which means you will need to reorganize your
>> sources so that the
>> sourcepath and module path should be organized in "module path layout",
>> meaning that there
>> is an extra filename component to separate the package hierarchies for
>> the various modules
>> being compiled.  It is expected, but not required, that there is a
>> relationship between the
>> name of that filename component and the module name.
>>
> So to be sure about where a module is and what its name is, tools like
> ant, have
> to open the module-info.java file and read it? If ant looks at a
> directory and finds
> both module-info.java and java sources, then it probably is a single
> module compile.
>
> If it only finds a module-info.java file and the module_name inside it,
> sort of corresponds
> to the directory (or is the directory name encoded into the
> module-info.java file)
> then it is multiple module setup?
>
> I was hoping that when I found a module-info.java file, the directory in
> which it resides
> is the name of the module. Fast and convenient.....
>
> //Fredrik
>

If -modulepath is set but not -classpath, then that implies multi-module
mode.

Otherwise, if there is a module-info on the command line or source path
or class path, then it is single module mode, else zero module mode.

The rules were designed for ease of migration of existing code.

The truth about the name of the module lies solely in the module-info file,
as will eventually be defined in JLS. JLS does not in general impose any
requirements on the file system layout, leaving that up to "the host 
system".
Just as the classes for a package do not have to live in a directory 
structure
matching the package hierarchy, so too for modules. But in both cases,
convention and convenience will likely imply a strong correspondence.

-- Jon