On 03/16/2017 10:48 AM, Stephen Colebourne wrote:
Automodules exist to provide a means for gradual migration from a
non-modular world to a modular one. Unfortunately, they have proven
controversial with most of the EG and Jigsaw list. This thread seeks
to bring together some of the proposals to remove automodules.
The key issue is that automodules force a module author to pick the
name of modules that they do not control. Note that while a better
module naming strategy (discussed elsewhere) reduces the potential for
issues, a module author should never, ever be asked to guess somebody
else's name. That is the fundamentally broken concept.
These are the possible alternatives that remove the need for guessing
a name that I can see (without changing JPMS so much that Java 9 is
delayed again):
[...]
3) Remove the concept of automodules entirely
Migration would be slower, but safer. Tooling might evolve to add
module-info dynamically as part of the build or runtime system, or by
editing all the jar files in Maven Central to have an auto-generated
module name.
Indeed, it would be relatively easy to introduce a tool that would
assemble an arbitrary set of JARs into a module graph, using a
configuration descriptor for only the most advanced cases (pruning the
service list, specifying reflection capabilities if they are more
specific than "open all"). Such a tool would be superior to automatic
modules in many ways.
This approach has other important advantages: zero magic (particularly
if a tool can describe what it has done concisely), and choice of
implementation.
Even as I was writing this, a colleague of mine sent me a message that
he has already independently created such a tool. The URL is:
https://github.com/moditect/moditect
Er, I can't think of a viable option 4.
4) Support a mode of operation where the descriptor is external to the
module content.
Containers are already going to be doing this anyway after all. This is
similar, in a way, to option 3 where tooling (or a person, if we can
ever break away from this idea of requiring bytecode for this purpose)
would be able to establish the modular environment without modifying the
artifacts. This is a model that we use today with success.
--
- DML
