[MRESOLVER-298] Make javax.inject optional again

[cstamas]

javax.inject is and should be optional (used only when Guice and/or Sisu is being used), but in case SL is being used no javax.inject should be needed.

This rule was violated in 1.9.0 commit 5566bd5 where javax.inject.Provider was used in conjuction with SL as well.

This fix introduces NameMappers helper static class that constructs name mappers, and javax.inject.Provider classes are used ONLY when in Guice/Sisu, are NOT used with conjunction of SL.

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https://issues.apache.org/jira/browse/MRESOLVER-298

[michael-o]

Call me stupid, but what makes it optional now? That the providers don't appear in the annoations and this avoids the transitive dep to javax.inject?

[cstamas]

Call me stupid, but what makes it optional now? That the providers don't appear in the annoations and this avoids the transitive dep to javax.inject?

No dependency or scope was changed, it was code only, here https://github.com/apache/maven-resolver/pull/235/files#diff-530cadfdf6c10eff31703c1c50c7121f9c72c64a4f55c156428c7cc1113e6950R77-R86 This private static method is used with default ctor (when SL is used) and expected Provider on classpath. This is not the case anymore.

Simple proof: the "demo snippets" now work from IDE (they have main method), while on current master they do NOT work due same issue (javax.inject is present in test scope).

[michael-o]

Call me stupid, but what makes it optional now? That the providers don't appear in the annoations and this avoids the transitive dep to javax.inject?

No dependency or dep scope was changed, it was code, here https://github.com/apache/maven-resolver/pull/235/files#diff-530cadfdf6c10eff31703c1c50c7121f9c72c64a4f55c156428c7cc1113e6950R77-R86 This private static method is used with default ctor (when SL is used) and expected Provider on classpath. This is not the case anymore.

Simple proof: the "demo snippets" now work from IDE (they have main method), before this change, on current master they do NOT work due same issue (as javax.inject is only in test scope).

This is basically what I meant. The Provider had to be there...