INT-3383: Update to Smack 4.0.0

[Flowdalic]

It is no longer necessary to supress Smack path warnings.

Delete custom smack-config.xml, as all it did was disabling
certain (important) SASL mechanisms. Also remove the unit test that
verified this.

Some unit tests mock ChatManager and Chat for no reason, delete
those lines.

XMPPConnection.getHost() and .getPort() are only valid after the
connection got established, due the fact that those information is
often only available after a DNS SRV lookup was performed. Remove the
lines in unit tests that verified their value.

Remove the truststorePath example in documentation, since Smack 4.0 no
longer provides support for providing a custom truststore. Instead
ConnectionConfiguration in Smack 4.0 allows to set a custom SSLContext
(which then again can provide a TrustManager that uses a custom
truststore).

[artembilan]

@Flowdalic, before we start review it we should be sure that you signed the CLA.
From other side you are right: would be better to upgrade it already to GA, rather than RC, especially with such big changes.

Thank you, anyway!

[Flowdalic]

@artembilan Just siged the CLA so

I have signed and agree to the terms of the SpringSource Individual Contributor License Agreement.

I have no strong opinion about when Smack is updated in spring-integration. Just wanted to point out that 1. there is a newer version with important security fixes and 2. this version is now also available from maven central. The changes to spring itself are minimal, but users of Smack should note that Smack 4.0 comes with a slightly changed API. The important thing is that spring-integration will switch from the (very) old currently used Smack version to 4.0 at some point in the future.

[garyrussell]

Thanks for this; we can't release 4.0 GA depending on an RC, but we can certainly test with it (travis is building this PR now as I "speak").

If all is well, we can target the update to 4.0.1, unless smack is released by the end of the week (or Monday at the latest).

[Flowdalic]

Updated to use Smack 4.0.0-rc2. Note that some spring-integration unit tests fail because spring-ws is not yet upgraded to Smack 4.0. See also spring-projects/spring-ws#23

I'm not sure how this kind of dependency updates is usually handled in spring, so please advise. Thank you :)

[artembilan]

@Flowdalic, thank you for updating the PR. Starting to review...

[artembilan]

Well, I see there is an issue with new Smack and old Spring WS.
Is Smack 4.0 compatible with a Smack 3.0? I mean can we have in the classpath both versions?
I'm not sure how quickly the Spring WS (2.3.0) with new Smack will be released so we should be carefull with the new Smack for SI and old one for WS, because we can't release our project with a milestone dependency.
Just in case: can we live with both Smacks in the CP?

[Flowdalic]

You would need some kind of isolation to have two different versions of the same library loaded (like OSGi). Not sure if this is true or possible in Spring. But even if you could do it, then there is also the API change from Smack 3 to 4. How should the user/JVM decide which version to load?

That's actually what I tried to explain in my JIRA comment: I don't know how the Spring project handles these situations, as it has many release lines, other stuff and sure some policies. All I can say is that the Smack API in spring-integration and spring-ws needs to be compatible. So it's either Smack 3 for both or Smack 4. How you achieve that is up to you.
BTW: I'm not sure if those inter-dependencies are a good design, as it causes situations like we have now, but hadn't time yet to look closer at it.

[artembilan]

That's all.
Actually I can live with all those changes in tests if they pass, although I want to know reasons.
My main concern is about compatibility with Spring WS with Smack 3.1.

Thanks

[artembilan]

OK, @Flowdalic, nothing to complain about.
Will be merged on it's time.

Thank you!

[artembilan]

Merged via 714db85
Note: we left SI-WS with Smack 3.2, because we can live with that tiny case, when SI will be with Smack 4.0, but WS is still with Smack 3.2. It hardly ever is to use WS with XMPP transport.

Thanks you!