[MNG-7129] http repo refactoring for java8

[AlexanderAshitkin]

Cache repositories refactoring for java8 - using optionals instead of nullables

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[michael-o]

I believe that this entire code needs to be rewritten to use Wagon instead of manually fiddling with HttpClient.

[AlexanderAshitkin]

I believe that this entire code needs to be rewritten to use Wagon instead of manually fiddling with HttpClient.

good point and should not be a big deal. will try to do it in following prs

[gnodet]

I believe that this entire code needs to be rewritten to use Wagon instead of manually fiddling with HttpClient.

good point and should not be a big deal. will try to do it in following prs

Not necessarily instead, but a simple abstraction layer would allow to use the default http repository or use wagon as an alternative and more versatile provider.

[AlexanderAshitkin]

I believe that this entire code needs to be rewritten to use Wagon instead of manually fiddling with HttpClient.

good point and should not be a big deal. will try to do it in following prs

Not necessarily instead, but a simple abstraction layer would allow to use the default http repository or use wagon as an alternative and more versatile provider.

Agree. It could be reworked as we like in the future, just at this point it will be a small cleanup which doesnt have much of implications. also, it was tested, so it will be great to merge it.

Conceptually i agree with more comprehensive rework in future

[gnodet]

I believe that this entire code needs to be rewritten to use Wagon instead of manually fiddling with HttpClient.

good point and should not be a big deal. will try to do it in following prs

Not necessarily instead, but a simple abstraction layer would allow to use the default http repository or use wagon as an alternative and more versatile provider.

Agree. It could be reworked as we like in the future, just at this point it will be a small cleanup which doesnt have much of implications. also, it was tested, so it will be great to merge it.

Conceptually i agree with more comprehensive rework in future

I'm going to merge. What's the reasoning for using an Optional instead of throwing an exception ?

[AlexanderAshitkin]

I'm going to merge. What's the reasoning for using an Optional instead of throwing an exception ?

Hi. The rationale is that cache misses are natural. Optionals allow to isolate normal flow from real errors (like transport and format issues) and to avoid flood of not so useful "not found" exceptions. If it is necessary to assert a resource presence it should be done in cache logic by a caller