Update to Java 21 by OwenCorrigan76 · Pull Request #119 · strimzi/kafka-access-operator

OwenCorrigan76 · 2026-02-09T15:33:25Z

This PR moves the Strimzi Kafka Access Operator repo to Java 21.

scholzj

Just some quick notes. Thanks for looking into it.

scholzj · 2026-02-09T18:03:46Z

install/000-Namespace.yaml

 kind: Namespace
 metadata:
-  name: strimzi-access-operator
+  name: myproject


These changes should not be here?

Thanks for the review. Careless mistake. Fixed

scholzj · 2026-02-09T18:04:58Z

.checkstyle/checkstyle.xml

+        <!-- Javadoc -->
+        <module name="JavadocStyle">
+            <property name="checkEmptyJavadoc" value="true"/>
+            <property name="checkFirstSentence" value="false"/>
+        </module>


It makes sense to move Javadoc validation to Checkstyle. But you should likely mirror the rules from other repos. See for example here: https://github.com/strimzi/strimzi-kafka-bridge/pull/1067/changes

Assuming there are more changes it needs in the code, opening a separate PR might make sense (it is not dependent on Java 21 anyway).

Reverted this. I will work on this in a new PR as suggested. Thanks

scholzj · 2026-02-09T18:06:04Z

api/pom.xml

+        <maven.compiler.source>21</maven.compiler.source>
+        <maven.compiler.target>21</maven.compiler.target>


Do we really need to mirror this in all modules? Why isn't that only in the main pom.xml? The same for javadoc.fail.on.warnings now, when it is disabled everywhere? (assuming it is still needed at all)

Removed from all but main pom.

scholzj · 2026-02-09T18:06:55Z

Dockerfile


 # Set JAVA_HOME env var
-ENV JAVA_HOME=/usr/lib/jvm/jre-17
+ENV JAVA_HOME=/usr/lib/jvm/jre-21


Suggested change

ENV JAVA_HOME=/usr/lib/jvm/jre-21

ENV JAVA_HOME=/usr/lib/jvm/jre-${JAVA_VERSION}

im-konge

One comment + I agree with the Jakub's comments there. Thanks for looking on this :)

install/050-Deployment.yaml

im-konge

LGTM, thanks.

scholzj

So, you disabled the Javadoc validation from the JDK. But you do not seem to replace it with the Checkstyle Javadoc validation as we do it in other projects. I think that is something that needs to be done here or in a separate PR before this one (whichever you prefer). But I do not think we should just drop the validation now and say that we fix it some time later.

scholzj · 2026-02-14T15:41:14Z

development-docs/DEV_GUIDE.md

+example, to build docker images that have the Java 21 JRE installed use `JAVA_VERSION=21 make docker_build`. If not
+present, the container images will use Java **21** by default.


Same as above - does this really make sense given we support Java 21 only?

scholzj · 2026-02-14T15:41:19Z

development-docs/DEV_GUIDE.md

+it to the desired Java version. For example, for building with Java 21 you can use `export JAVA_VERSION_BUILD=21`.

-> *Note*: Operator currently developed and tested with Java 17.
+> *Note*: Operator currently developed and tested with Java 21.


I know you did not added this section. But given we basically support Java 21 only - what point does it have?

ppatierno · 2026-02-15T14:18:38Z

@OwenCorrigan76 regarding what Jakub mentioned, so replacing the Javadoc validation with the Checkstyle one, you could get some inspiration from what was done on the bridge here strimzi/strimzi-kafka-bridge#1067 (using the bridge as example because it's a project which is size-wise similar to kafka access operator). Let me know if you need any advice/help/insights to better understand what's needed.

OwenCorrigan76 · 2026-02-17T09:33:29Z

Thanks a mil for the comments guys. Will address today.

Signed-off-by: ocorriga <ocorriga@redhat.com>

scholzj · 2026-02-17T10:44:27Z

@OwenCorrigan76 The point of the Javadoc changes is that we do want to have the Javadoc changes validated. So you should not be disabling it without having the replacement first. So you can:

First do the PR to move the validation of the Javadocs to Checkstyle and disable the failure on Javadoc warnings. I would say that you should have failure on errors ever disabled.
Do all of it in a single PR
Fix the Javadoc to not have errors and warnings in Java 21, but I think that is pretty hard. So the previous 2 options are the better ones.

Signed-off-by: ocorriga <ocorriga@redhat.com>

OwenCorrigan76 · 2026-02-17T13:08:52Z

Thanks @scholzj. I think this should now be ok?? I've added a suppression for Systemtests and unit tests as is done in other repos. Is that ok?

There is some other failure on the build around make: *** [Makefile.docker:27: docker_build] Error 1 that I must investigate now.

im-konge · 2026-02-17T18:19:39Z

.checkstyle/suppressions.xml

+    <suppress checks=".*"
+              files="systemtest[/\\].*\.java"/>


This is not a good thing IMO.
By this, you will completely disable all the checks - including * imports, unused imports etc.
Did you saw this in some other repo? We have these checks for STs disabled only for the generated classes, as we are not able to do anything with them (this is for the operators repo).

scholzj · 2026-02-17T22:43:20Z

Thanks @scholzj. I think this should now be ok?? I've added a suppression for Systemtests and unit tests as is done in other repos. Is that ok?

I think it is definitely fine to have a supression for tests and system tests. But as mentioned by Lukas, It should be minimized. So probably Javadocs only. And f it needs something more than just the Javadocs, please share what it complains about and we can have a look. In general, we should aim to remove these suppressions. But we can leave the STs Javadocs for later. You can check the Operators suppressions to see what we suppress there: https://github.com/strimzi/strimzi-kafka-operator/blob/main/.checkstyle/suppressions.xml

There is some other failure on the build around make: *** [Makefile.docker:27: docker_build] Error 1 that I must investigate now.

It seems that there was some Red Hat RPM repo outage. Restarting the build seemed to have worked.

Signed-off-by: ocorriga <ocorriga@redhat.com>

OwenCorrigan76 · 2026-02-19T09:51:43Z

@scholzj @im-konge I have removed the supress all systemtests and just supressed checkstyle checks from Javadocs.

im-konge · 2026-02-19T17:05:05Z

.checkstyle/suppressions.xml

    <suppress checks=".*"
              files="io[/\\]strimzi[/\\]kafka[/\\]access[/\\]model[/\\].*(Builder|Fluent|FluentImpl)\.java"/>
+    <suppress checks="JavadocMethod|JavadocType|JavadocVariable|MissingJavadocType|MissingJavadocMethod"
+              files="(systemtest|src[/\\]test[/\\]java)[/\\].*\.java"/>


Suggested change

files="(systemtest|src[/\\]test[/\\]java)[/\\].*\.java"/>

files="systemtest[/\\]src[/\\]test[/\\]java)[/\\].*\.java"/>

I think it should be like this? Or is | there on purpose?

and without .java, you don't need it there (based on https://github.com/strimzi/strimzi-kafka-operator/blob/main/.checkstyle/suppressions.xml#L49)

Or if you are trying to suppress it for both STs and for regular tests, I think it should be done separately. Because this is a bit confusing for me.

Signed-off-by: ocorriga <ocorriga@redhat.com>

im-konge

I think this will work fine, LGTM.

OwenCorrigan76 added this to the 0.3.0 milestone Feb 9, 2026

OwenCorrigan76 force-pushed the Update_Java_21 branch 2 times, most recently from 20274e9 to 54276dd Compare February 9, 2026 16:21

scholzj reviewed Feb 9, 2026

View reviewed changes

im-konge reviewed Feb 9, 2026

View reviewed changes

install/050-Deployment.yaml Outdated Show resolved Hide resolved

OwenCorrigan76 requested review from im-konge, katheris and scholzj February 13, 2026 13:49

im-konge approved these changes Feb 13, 2026

View reviewed changes

scholzj reviewed Feb 14, 2026

View reviewed changes

ocorriga added 3 commits February 17, 2026 09:46

Update to Java 21

47c4e49

Signed-off-by: ocorriga <ocorriga@redhat.com>

Update spotbugs

c92a5d5

Signed-off-by: ocorriga <ocorriga@redhat.com>

Address Comments

f514311

Signed-off-by: ocorriga <ocorriga@redhat.com>

OwenCorrigan76 force-pushed the Update_Java_21 branch from 8d1e07e to f0e05c6 Compare February 17, 2026 10:18

Address Comments & revert failOnWarnings

6217d2c

Signed-off-by: ocorriga <ocorriga@redhat.com>

OwenCorrigan76 force-pushed the Update_Java_21 branch from f0e05c6 to 6217d2c Compare February 17, 2026 10:34

Add Checkstyle checks and update pom

2fe444a

Signed-off-by: ocorriga <ocorriga@redhat.com>

im-konge reviewed Feb 17, 2026

View reviewed changes

im-konge self-requested a review February 17, 2026 18:20

Remove all systemtest supression

c9dc9fb

Signed-off-by: ocorriga <ocorriga@redhat.com>

im-konge reviewed Feb 19, 2026

View reviewed changes

Fix checkstyle.xml

364bb04

Signed-off-by: ocorriga <ocorriga@redhat.com>

im-konge approved these changes Feb 23, 2026

View reviewed changes

		<maven.compiler.source>21</maven.compiler.source>
		<maven.compiler.target>21</maven.compiler.target>

	ENV JAVA_HOME=/usr/lib/jvm/jre-21
	ENV JAVA_HOME=/usr/lib/jvm/jre-${JAVA_VERSION}

		example, to build docker images that have the Java 21 JRE installed use `JAVA_VERSION=21 make docker_build`. If not
		present, the container images will use Java 21 by default.

	files="(systemtest\|src[/\\]test[/\\]java)[/\\].*\.java"/>
	files="systemtest[/\\]src[/\\]test[/\\]java)[/\\].*\.java"/>

Comments

Conversation

OwenCorrigan76 commented Feb 9, 2026

Uh oh!

scholzj left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

OwenCorrigan76 Feb 13, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

im-konge left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

im-konge left a comment

Choose a reason for hiding this comment

Uh oh!

scholzj left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

ppatierno commented Feb 15, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

OwenCorrigan76 commented Feb 17, 2026

Uh oh!

scholzj commented Feb 17, 2026

Uh oh!

OwenCorrigan76 commented Feb 17, 2026

Uh oh!

Choose a reason for hiding this comment

Uh oh!

scholzj commented Feb 17, 2026

Uh oh!

OwenCorrigan76 commented Feb 19, 2026

Uh oh!

im-konge Feb 19, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

im-konge left a comment

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

4 participants

OwenCorrigan76 Feb 13, 2026 •

edited

Loading

ppatierno commented Feb 15, 2026 •

edited

Loading

im-konge Feb 19, 2026 •

edited

Loading