Code cleanup

[basil]

A series of code cleanup changes for this repository. Most of these changes fix IntelliJ or Error Prone warnings. I kept each commit separate. Each commit message should be self-explanatory, but if anything is unclear I am happy to provide further explanation. Also, feel free to revert any specific cleanup commits that are unwanted.

CC: @jenkinsci/hacktoberfest

[basil]

Error was:

{noformat}
[2019-10-11T19:51:04.148Z] [ERROR] org.jenkinsci.plugins.workflow.ArtifactManagerTest Time elapsed: 1.661 s <<< ERROR!
[2019-10-11T19:51:04.148Z] java.lang.Error: Failed to build image (1): 32edfdd58111
[2019-10-11T19:51:04.148Z] at org.jenkinsci.test.acceptance.docker.Docker.build(Docker.java:131)
[2019-10-11T19:51:04.148Z] at org.jenkinsci.test.acceptance.docker.Docker.build(Docker.java:174)
[2019-10-11T19:51:04.148Z] at org.jenkinsci.test.acceptance.docker.Docker.build(Docker.java:160)
[2019-10-11T19:51:04.148Z] at org.jenkinsci.test.acceptance.docker.Docker.build(Docker.java:140)
[2019-10-11T19:51:04.148Z] at org.jenkinsci.plugins.workflow.ArtifactManagerTest.prepareImage(ArtifactManagerTest.java:91)
[2019-10-11T19:51:04.148Z] at org.jenkinsci.plugins.workflow.ArtifactManagerTest.doPrepareImage(ArtifactManagerTest.java:81)
[2019-10-11T19:51:04.148Z] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[2019-10-11T19:51:04.148Z] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[2019-10-11T19:51:04.148Z] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[2019-10-11T19:51:04.148Z] at java.lang.reflect.Method.invoke(Method.java:498)
[2019-10-11T19:51:04.148Z] at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
[2019-10-11T19:51:04.148Z] at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
[2019-10-11T19:51:04.148Z] at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
[2019-10-11T19:51:04.148Z] at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
[2019-10-11T19:51:04.148Z] at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:365)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.junit4.JUnit4Provider.executeWithRerun(JUnit4Provider.java:273)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:238)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:159)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:384)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:345)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.booter.ForkedBooter.execute(ForkedBooter.java:126)
[2019-10-11T19:51:04.148Z] at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:418)
{noformat}

This doesn't seem related to my changes. Trying another build.

[basil]

Trying another build.

[basil]

The most recent run passed the Docker portion, but failed in Javadoc generation. I can't reproduce the error on my local machine with OpenJDK 1.8.0_222 running mvn javadoc:jar. Since the Javadoc error on ci.jenkins.io is related to a missing reference, I'll first try reverting 0303bc1 (the only commit where I added a reference) as a shot in the dark. If that doesn't help, I'll try digging further to reproduce the problem on my local machine.

[basil]

I think I figured it out. Some imports I removed in package-info.java were actually needed by the Javadoc. Thanks, IntelliJ (not). Anyway, I added them back and am hopefully this will fix the problem. Of course, now I am running into Remoting problems on the Windows agent, so I will close and reopen to get yet another build.

[basil]

Windows agent is still broken, will try again tomorrow.

[halkeye]

I believe for java 11 it'll actually fail if the javadoc is there but isn't correct. It'll be fine if not there. Or is correct.