MINOR: Upgrade gradle to 9.6.1

[Parkerhiphop]

Update Gradle from 9.4.1 to 9.6.1, including the wrapper distribution
checksum and Kafka's wrapper JAR checksum references.

Updated files:

• gradle/dependencies.gradle
• gradle/wrapper/gradle-wrapper.properties
• gradlew
• wrapper.gradle

Verified locally with Gradle 9.6.1:

• ./gradlew --version reports Gradle 9.6.1

Build a JAR and run it

• ./gradlew jar

Build source JAR

• ./gradlew srcJar

Build aggregated javadoc

• ./gradlew aggregatedJavadoc --no-parallel

Build javadoc and scaladoc

• ./gradlew javadoc
• ./gradlew javadocJar
• ./gradlew scaladoc
• ./gradlew scaladocJar
• ./gradlew docsJar

Running a particular unit/integration test

• ./gradlew clients:test --tests RequestResponseTest
• ./gradlew streams:integration-tests:test --tests RestoreIntegrationTest

Running a particular test method within a unit/integration test

• ./gradlew clients:test --tests org.apache.kafka.clients.MetadataTest.testTimeToNextUpdate
• ./gradlew streams:integration-tests:test --tests org.apache.kafka.streams.integration.RestoreIntegrationTest.shouldRestoreNullRecord

Building a binary release gzipped tarball

• ./gradlew clean releaseTarGz

Building auto-generated messages

• ./gradlew processMessages processTestMessages

Running a task for a specific project

• ./gradlew core:jar

Listing all gradle tasks

• ./gradlew tasks

Installing all projects to the local Maven repository

• ./gradlew -PskipSigning=true publishToMavenLocal

Building the test JAR

• ./gradlew testJar

Running code quality checks

Checkstyle

• ./gradlew checkstyleMain checkstyleTest spotlessCheck

SpotBugs

• ./gradlew spotbugsMain spotbugsTest -x test

Reviewers: Chia-Ping Tsai chia7712@gmail.com

[chia7712]

@Parkerhiphop Thanks for this patch. Would you mind testing more commands listed in the README? We encountered numerous issues when upgrading Gradle before

[m1a2st]

Test on my local machine, all passed

#	Command (from README.md)	Result
1	./gradlew --version	✅ PASS — reports Gradle 9.6.1
2	./gradlew tasks	✅ BUILD SUCCESSFUL
3	./gradlew jar	✅ BUILD SUCCESSFUL (164 tasks, 158 executed)
4	./gradlew clients:test --tests RequestResponseTest	✅ BUILD SUCCESSFUL — 45 test cases, 0 failed
5	./gradlew streams:integration-tests:test --tests RestoreIntegrationTest	✅ BUILD SUCCESSFUL — 38 test cases, 0 failed
6	./gradlew javadoc	✅ BUILD SUCCESSFUL (85 tasks)
7	./gradlew scaladoc	✅ BUILD SUCCESSFUL (36 tasks)
8	./gradlew -PskipSigning=true publishToMavenLocal	✅ BUILD SUCCESSFUL — 730 tasks, 65 publish-related tasks executed

[Parkerhiphop]

@Parkerhiphop Thanks for this patch. Would you mind testing more commands listed in the README? We encountered numerous issues when upgrading Gradle before

Yes. I verified more test commands list in the README and attached them in the description.

[Parkerhiphop]

Test on my local machine, all passed

Command (from README.md) Result

1 ./gradlew --version ✅ PASS — reports Gradle 9.6.1
2 ./gradlew tasks ✅ BUILD SUCCESSFUL
3 ./gradlew jar ✅ BUILD SUCCESSFUL (164 tasks, 158 executed)
4 ./gradlew clients:test --tests RequestResponseTest ✅ BUILD SUCCESSFUL — 45 test cases, 0 failed
5 ./gradlew streams:integration-tests:test --tests RestoreIntegrationTest ✅ BUILD SUCCESSFUL — 38 test cases, 0 failed
6 ./gradlew javadoc ✅ BUILD SUCCESSFUL (85 tasks)
7 ./gradlew scaladoc ✅ BUILD SUCCESSFUL (36 tasks)
8 ./gradlew -PskipSigning=true publishToMavenLocal ✅ BUILD SUCCESSFUL — 730 tasks, 65 publish-related tasks executed

Thanks for testing!

[chia7712]

Gradle Test Run :core:test > Gradle Test Executor 1 > UserClientIdQuotaTest > testThrottledRequest(String) > testThrottledRequest(String).groupProtocol=consumer FAILED
    java.lang.NoClassDefFoundError: Could not initialize class org.bouncycastle.operator.DefaultSignatureAlgorithmIdentifierFinder
        at org.apache.kafka.test.TestSslUtils$CertificateBuilder.generate(TestSslUtils.java:441)
        at org.apache.kafka.test.TestSslUtils$CertificateBuilder.generate(TestSslUtils.java:428)
        at org.apache.kafka.test.TestSslUtils$SslConfigsBuilder.buildJks(TestSslUtils.java:666)
        at org.apache.kafka.test.TestSslUtils$SslConfigsBuilder.build(TestSslUtils.java:656)
        at org.apache.kafka.security.JaasTestUtils.sslConfigs(JaasTestUtils.java:291)
        at org.apache.kafka.security.JaasTestUtils.securityConfigs(JaasTestUtils.java:342)
        at org.apache.kafka.security.JaasTestUtils.securityConfigs(JaasTestUtils.java:315)
        at kafka.api.IntegrationTestHarness.clientSecurityProps(IntegrationTestHarness.scala:174)
        at kafka.api.IntegrationTestHarness.doSetup(IntegrationTestHarness.scala:133)
        at kafka.api.IntegrationTestHarness.setUp(IntegrationTestHarness.scala:118)
        at kafka.api.BaseQuotaTest.setUp(BaseQuotaTest.scala:85)
        at kafka.api.UserClientIdQuotaTest.setUp(UserClientIdQuotaTest.scala:35)

        Caused by:
        java.lang.ExceptionInInitializerError: Exception java.lang.NoSuchFieldError: Class org.bouncycastle.asn1.x509.X509ObjectIdentifiers does not have member field 'org.bouncycastle.asn1.ASN1ObjectIdentifier id_rsassa_pss_shake128' [in thread "Test worker"]
            at org.bouncycastle.operator.DefaultSignatureAlgorithmIdentifierFinder.<clinit>(Unknown Source)
            ... 12 more

8 tests completed, 8 failed

I guess the dependency order changed during the upgrade. We need to exclude bcprov-jdk15on from the core module.

    configurations {
      // To prevent a UniqueResourceException due the same resource existing in both
      // org.apache.directory.api/api-all and org.apache.directory.api/api-ldap-schema-data
      testRuntimeOnly.exclude module: 'api-ldap-schema-data'
      testFixturesImplementation.exclude group: 'org.bouncycastle', module: 'bcprov-jdk15on'
      testCompileClasspath.exclude group: 'org.bouncycastle', module: 'bcprov-jdk15on'
      testRuntimeClasspath.exclude group: 'org.bouncycastle', module: 'bcprov-jdk15on'
    }

[Parkerhiphop]

Yes. I excluded bcprov-jdk15on from the core module's test compile/runtime classpaths.

I also verified it locally with:

./gradlew core:dependencyInsight --configuration testRuntimeClasspath --dependency bcprov-jdk15on
./gradlew core:test --tests kafka.api.UserClientIdQuotaTest.testThrottledRequest

The dependency insight output confirms that bcprov-jdk15on is no longer present in :core:testRuntimeClasspath:

No dependencies matching given input were found in configuration ':core:testRuntimeClasspath'

The targeted UserClientIdQuotaTest.testThrottledRequest test also passed locally.