Java: async getPubSubMessage.

[Yury-Fridlyand]

Issue #, if available:
N/A

Description of changes:
#1662 (comment)

TODO list:

• Impl
• UT
• IT

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[Yury-Fridlyand]

Tested with Wireshark - Not my fault ©

[jduo]

LGTM for the impl. Will examine the tests more.

[jduo]

There's no reason to use an atomic if the only place it's used is a synchronized method. The use case for atomics is usually that you check-and-set it, then potentially lock.

[Yury-Fridlyand]

I know. I keep trying to get rid of synchronized.

[jduo]

Could be package-private.

[Yury-Fridlyand]

Compilation fails - BaseClient from glide.api uses it.

[jduo]

That seems strange that it uses it directly. I would've thought it goes through MessageHandler.

[jduo]

OK I see, you are creating a MessageHandler before the builder, then passing the handler in when creating the channel but passing the queue in to the client's constructor.

This is exposing a class from a non-public package to a non-private field in a public/protected class in an exposed package.

I am actually seeing that on a bunch of BaseClient classes. Let's discuss offline.

[jduo]

Separate from the above issue of internal classes in public APIs, I think BaseClient should not have a MessageQueue. It should always route through a MessageHandler that accesses a MessageQueue. I would MessageQueue a static inner class of MessageHandler (package-private for unit testing).

This would make it clear a MessageQueue can't really be on its own and is always tied to a MessageHandler.

[ikolomi]

@Yury-Fridlyand
Please make sure there are no commits such as:
"
I HATE YOU SPOTLESS
Revert some stuff.
O, great god of test, accept this.
"
They might be viewed a sign of unprofessional work by our customers and we dont want that. Better yes, squash the all the commits into one, so the whole work can be easily compartmentalized

[jduo]

@Yury-Fridlyand , let's rebase this on main now since it has the comment and API changes. Of particular note:

• GlideStrings are now used instead of Strings for PubSubMessages.
• Order of channel and message parameters swapped for publish() functions.
• New integration tests in PubSubTests

[Yury-Fridlyand]

Commits are squashed at the moments of merge.

[ikolomi]

Approving make sure the commit messages are cleaned up