Type of change

• Task

Description

We are currently using the Javadoc itself to validate the Javadoc comments by configuring it to fail on warnings. This is not the best solution:

• It is not configurable, you either treat all warnings as errors or none of them. So we can only disable it for a whole module or not.
• It changes with various Java releases. We had to significantly change/extend the Javadocs to move to Java 11 and 17. The same should be expected once we move to Java 21.
• The validation is not perfect and does not capture some kinds of missing/wrong parameters, does not handle templates, or validates the Javadoc format.

This PR moves the Javadoc validation from the Javadoc executable and the Javadoc Maven plugin to check-style. This should give us many improvements:

• The same validation regardless of the Java version
• Better configurability:
  • We can better control what exactly we want from the Javadocs
  • We can better control what files it applies to not just by excluding the whole module but also particular package or files (for example we could exclude the generated files)
• It provides better validation. For example by validating the comments style etc.

This PR adds the checks for the JavaDocs to the check-style settings and disables the raising of warnings as errors in the Javadoc plugin. But it keeps the same modules as before excluded for the time being:

• The api module
• The test module
• The systemtest module
• All unit and integration tests

It also updates the Checkstyle and JavaDoc plugin versions.

Most of the additional JavaDoc issues it found are already fixed in #10525. This PR fixes a few more.

Checklist

• Try your changes from Pod inside your Kubernetes and OpenShift cluster, not just locally