MINOR: Cleanup Core Module- Scala Modules (2/n)

[sjhajharia]

Now that Kafka Brokers support Java 17, this PR makes some changes in
core module. The changes in this PR are limited to only the Scala files
in the Core module's tests. The unit tests module is still pending. It
shall follow next. The changes mostly include:

• Collections.emptyList(), Collections.singletonList() and
  Arrays.asList() are replaced with List.of()
• Collections.emptyMap() and Collections.singletonMap() are replaced
  with Map.of()
• Collections.singleton() is replaced with Set.of()

To be clear, the directories being targeted in this PR are:
KafkaApisTest.scala

Reviewers: PoAn Yang [email protected], Ming-Yen Chung [email protected], Yung [email protected], TengYao Chi [email protected], Ken Huang [email protected]

[FrankYang0529]

@sjhajharia, I think we can do more in this PR.

1. mutable.HashSet -> util.Set.of

   kafka/core/src/test/scala/unit/kafka/server/KafkaApisTest.scala

   Lines 10731 to 10733 in 2cd733c

   	val resources = new mutable.HashSet[String]
   	resources.add("test1")
   	resources.add("test2")

2. util.HashMap -> util.Map.of

   kafka/core/src/test/scala/unit/kafka/server/KafkaApisTest.scala

   Lines 5511 to 5523 in 2cd733c

   	val erroneousPartitions: util.Map[TopicIdPartition, ShareFetchResponseData.PartitionData] = new util.HashMap()
   	erroneousPartitions.put(
   	tp2,
   	new ShareFetchResponseData.PartitionData()
   	.setPartitionIndex(1)
   	.setErrorCode(Errors.UNKNOWN_TOPIC_OR_PARTITION.code)
   	)
   	erroneousPartitions.put(
   	tp3,
   	new ShareFetchResponseData.PartitionData()
   	.setPartitionIndex(0)
   	.setErrorCode(Errors.UNKNOWN_TOPIC_OR_PARTITION.code)
   	)

[sjhajharia]

Thanks @FrankYang0529
Adding in the changes you suggested.

[frankvicky]

I think we can also remove the operations of asScala followed by asJava.
For example:

kafka/core/src/test/scala/unit/kafka/server/KafkaApisTest.scala

Lines 3016 to 3018 in c009eed

	actions.asScala.map { action =>
	acls.getOrElse(action.resourcePattern.name, AuthorizationResult.DENIED)
	}.asJava

[sjhajharia]

Thanks @frankvicky
Adding in the changes in a subsequent commit. Pls review when possible!

[m1a2st]

Thanks for this patch, LGTM

[sjhajharia]

Hey @chia7712 ,
Gentle reminder for the PR here!

[frankvicky]

@sjhajharia : LGTM assuming CI pass

[sjhajharia]

Thanks @frankvicky
The build looks good to me

[Yunyung]

Thanks for the PR. Left one minor.

Suggested change

	new util.HashSet(describeClusterResponse.nodes.values))
	util.Set.copyOf(describeClusterResponse.nodes.values))

[mingyen066]

Thanks for the cleanup.

There are many occurrences of this pattern:

val topicNames = new util.HashMap[Uuid, String]()
topicNames.put(topicId1, "foo1")
topicNames.put(topicId2, "foo2")

But in many of those cases, no additional topics are added later, so they can all be replaced with:

val topicNames = util.Map.of(topicId1, "foo1", topicId2, "foo2")

For example:
https://github.com/apache/kafka/blob/trunk/core/src/test/scala/unit/kafka/server/KafkaApisTest.scala#L7166C2-L7168C37

[mingyen066]

Could we use util.Set.copyOf ?

[sjhajharia]

Thanks @mingyen066 and @Yunyung for the review
I have added the suggestions. Please re-review

[sjhajharia]

Gentle reminder
@frankvicky

[mingyen066]

LGTM