non-API classes displayed by jrt filesystem

Jonathan Gibbons jonathan.gibbons at
Mon Oct 19 17:25:20 UTC 2015

On 10/19/2015 06:57 AM, Alan Bateman wrote:
> On 19/10/2015 13:12, Philippe Marschall wrote:
>> Hi
>> I'm toying around with the jrt filesystem [1]. I noted that non-API 
>> classes are shown for java modules (see attachment). I assume this is 
>> because jrt currently reports all classes in a module, not just the 
>> exported ones (and these classes are not exported). Assuming this is 
>> the intended behavior this is a bit inconvenient. One would have to 
>> parse the module-info.class to find out what is exported. Some 
>> possible solutions could include:
>>  * have a file attribute specific to the jrt filesystem "exported" to 
>> report whether a file/package is exported
>>  * have two subtrees in a module, eg. "all" and "exported"
> The behavior you see is intended and as Sundar said, it's not really 
> something for the file system to be concerned about. Also remember 
> there are qualified exports in the design and it would really 
> complicate things for the file system is be concerned with that.
> In any case, I think explorers are going to be useful to developers 
> because the module graph is essentially a new API to learn. If you are 
> only interested in the runtime that the tool is running on then you 
> might find ModuleFinder.ofInstalled().findAll() useful.
> -Alan

In time, javax.lang.model should also provide a way of examining modules 
that are distinct from those in the running system.

-- Jon

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