How to get jar file name by Module in Java 9?

Question

For example I have somefile-0.1.jar jar file which contains JPMS module. Besides, I have a reference Module somemodule to this module.

How to get jar file name by Module (using somemodule reference)? I've examined Module API but didn't find a way to do it.

Answer 1

There's no guarantee that module was loaded from a modular JAR. In any case, I think this is close to what you are looking for:

Module m = ...
ModuleLayer layer = m.getLayer();
if (layer != null) {
    ModuleReference mref = layer.configuration()
            .findModule(m.getName())
            .map(ResolvedModule::reference)
            .orElseThrow(() -> new RuntimeException("should not happen"));
}