Checkstyle

[tisonkun]

Thanks for your reviews @yiheng @guangxuCheng . I narrow the pending issues to three below.

1. ConstantNameCheck.

Generally disabled on private static final so that we narrow the impact to logger. All Logger are now logger and we can always do a reformat if further concern occurs. The problem is that I modify several logger from static final to private static final but I think it is OK because all of them is not and should not be used outside the class.

2. MethodNameCheck

I have no idea whether changes to method name would impact existing dependencies to TubeMQ. If we all agree that we can rename Subscribe as subscribe and TestXXX/test_xxx as testXxx I will turn on the checker and do a general reformatting.

3. RedundantModifier

Mostly it is about final in methods of interfaces. An ideal way in my mind is reformatted our method signature as the format below

<return type> methodName(
    T1 arg1,
    T2 arg2,
     ....
    TN arsN
) throws E1, E2 {
  ...
}

But it possibly impacts too much. An alternative is that we exclude METHOD_DEF property. It also makes sense to me.

CC @JunpingDu @gosonzhang

[yiheng]

+1

[tisonkun]

Thanks for your review @yiheng . Formally we send an approved review feedback for an approval.

Waiting for another reviewer @guangxuCheng since this pull request touch a lot of files.

[guangxuCheng]

@TisonKun I think we should add a checker for the licence to ensure that the header of the file contains the licence.

[tisonkun]

@guangxuCheng good point! Implemented by apache-rat-plugin https://github.com/Tencent/TubeMQ/pull/55/commits/2ea61bf768b1df80cc59cd2f73194d65b0ae19c0

[guangxuCheng]

LGTM +1