Remove calls to no-arg superclass constructor

[strkkk]

Hi,

In checkstyle project we adding a new check to detect calls to no-arg superclass constructor super();
checkstyle/checkstyle#7387
Our analysis shows that there are many violations of this check in your source code.
Analysis report:
https://strkkk.github.io/checkstyle/7363_3/spring-integration/index.html#A1

Can you please share your thoughts - it this calls should be removed or they can be kept for some reason?

Any feedback are appreciated.

[garyrussell]

There are other "rules" about empty blocks; our Sonar ruleset barks about them so an empty constructor is a violation of that rule.

There is also the EmptyBlock checkstyle rule.

We use super() only when a no-arg ctor is needed without extra code.

The rule you cite seems bogus to me - if you look at the byte code generated, the compiler adds the same super() implicitly.

[garyrussell]

If you can make the rule only trigger if there is extra code in the constructor, it might then be useful.

[strkkk]

Thank you for reply.

The rule you cite seems bogus to me - if you look at the byte code generated, the compiler adds the same super() implicitly.

Yeah, this is the reason why explicit call is redundant and goal of the check is to detect it.

[artembilan]

Well, I think we can change that super() call into a comment to satisfy all the rules around.
Also I think no one of them are aware about private empty ctors.

[garyrussell]

More discussion here about possibly changing EmptyBlock to allow empty no-arg CTORs.

[artembilan]

OK. So, placing "on-hold" until a resolution for linked issue in Checkstyle.

[strkkk]

@garyrussell

There is also the EmptyBlock checkstyle rule.

I checked this checkstyle rule and there is nothing about checking ctors. Can you please share checkstyle config that reports violation on empty ctor?

[garyrussell]

Interesting - I see checkstyle doesn't complain about empty CTORs and I just ran a test with our current Sonar rules and that passed too

https://sonar.spring.io/code?id=org.springframework.kafka%3Aspring-kafka-dist%3Asonar&selected=org.springframework.kafka%3Aspring-kafka-dist%3Asonar%3Aspring-kafka%2Fsrc%2Fmain%2Fjava%2Forg%2Fspringframework%2Fkafka%2Flistener%2FFoo.java

So this must have been some old rule on an older Sonar installation that is no longer triggered.

I therefore withdraw my objection.

[artembilan]

So, do we remove super(); from our classes to satisfy requirements here?

[garyrussell]

I would say so, yes (over time).