[BEAM-6554] Migrate from findbugs to spotbugs

[kennknowles]

This migrate dependencies from findbugs to spotbugs, with some fixes. There appear to be issues introduced in spotbugs.

• The change to suppression of a volatile warning was necessary even though it was already suppressed. Something about how spotbugs scopes the suppression made it not work for a nested lambda.
• There is still a failure claiming that the continuation parameter to SplittableProcessElementInvoker$Result is marked nullable, which is not the case. I have not yet decompiled to debug.

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Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---	---	---	---	---
Java
Python		---			---	---	---

[kennknowles]

@iemejia @adude3141 opening this for discussion

[kennknowles]

Oops. I'll revert this. I think we should default to settings that are good for a developer and have Jenkins jobs set things like -PxmlSpotbugs or some such. But later.

[adude3141]

definitely+1 on having decent developer defaults.

Unfortunately the Jenkins plugin requires xml output. And as findbugs/spotbugs support only single report format and I further was under the impression that findbugs should be removed, I simply switch to xml. Of course, this is a different story now.

Regarding that parameter, do we have other places where we have different configuration on jenkins? If so, would it make sense to extract some Jenkins-plugin which collects all this differences, so that we only either autodetect, we run on Jenkins (by checking some Jenkins env-var) or set only a single parameter, ciBuild=true or such.

[adude3141]

LGTM

anything I could do to help pushing this forward?

[kennknowles]

@adude3141 thanks! There's not much more to review. I noticed the same problem with the reports. I will set it to xml. Spotbugs itself in the build configuration has been no problem. I haven't had any minutes to spend on the second issue in the PR description. I think that is the main blocker, unless it is masking further errors.

[iemejia]

This needs a rebase, in principle looks ok also to me, will LGTM once the xml change is done and green.

[kennknowles]

OK. I got spotbugs happy. Now the blocker is adjusting the Jenkins job to either be flexible or to be OK with missing data.

[adude3141]

Now the blocker is adjusting the Jenkins job to either be flexible or to be OK with missing data.

I do not understand what is meant by that? Could you elaborate a bit?

[kennknowles]

@adude3141 I got an error something about findbugs/**/ file not found. I thought the directory might be renamed to spotbugs for the output reports. But the jobs seem happy right now. If this goes green, then great! It could have just been something completely different.

[kennknowles]

run java precommit

[adude3141]

ah, yes.

we need to change https://github.com/apache/beam/blob/master/.test-infra/jenkins/job_PreCommit_Java.groovy#L44-L46
as well to something like spotBugs { pattern('...') }

[kennknowles]

Finally got the right stuff in place for the dependency analysis plugin. Looks like Jira was down/ or rebooting when the website checker ran.