GH-2377: Add DestinationTopic.Properties#isRetryTopic() (#2589)

* GH-2377: Feature Request: Provide DestinationTopic.Properties#isRetryTopic() method

Resolve #2377

`DestinationTopic.Properties` has `isDltTopic()` and `isMainEndpoint()` but not for retry topic.
It adds `isRetryTopic()` method and adds tests to verify the correct behavior.

* Add `isRetryTopic()` instance method to `DestinationTopic.Properties`

* GH-2377: Provide DestinationTopic.Properties#isRetryTopic() method

Resolve #2377

`DestinationTopic.Properties` has `isDltTopic()` and `isMainEndpoint()` but not for retry topic.
It adds `isRetryTopic()` method and adds tests to verify the correct behavior.

* Add `isRetryTopic()` instance method to `DestinationTopic.Properties`

* Fix to align with code style

---------

Co-authored-by: sangboak.lee <[email protected]>

Author: echo304

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/DestinationTopic.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2022 the original author or authors.
+ * Copyright 2018-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -212,6 +212,10 @@ public boolean isDltTopic() {
 			return Type.DLT.equals(this.type);
 		}
 
+		public boolean isRetryTopic() {
+			return Type.RETRY.equals(this.type) || Type.SINGLE_TOPIC_RETRY.equals(this.type);
+		}
+
 		public String suffix() {
 			return this.suffix;
 		}

spring-kafka/src/test/java/org/springframework/kafka/retrytopic/DestinationTopicPropertiesFactoryTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2018-2021 the original author or authors.
+ * Copyright 2018-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -96,6 +96,7 @@ void shouldCreateMainAndDltProperties() {
 		DestinationTopic.Properties mainTopicProperties = propertiesList.get(0);
 		assertThat(mainTopicProperties.suffix()).isEqualTo("");
 		assertThat(mainTopicProperties.isDltTopic()).isFalse();
+		assertThat(mainTopicProperties.isRetryTopic()).isFalse();
 		DestinationTopic mainTopic = new DestinationTopic("mainTopic", mainTopicProperties);
 		assertThat(mainTopic.getDestinationDelay()).isEqualTo(0L);
 		assertThat(mainTopic.shouldRetryOn(0, new IllegalArgumentException())).isTrue();
@@ -110,6 +111,7 @@ void shouldCreateMainAndDltProperties() {
 	private void assertDltTopic(DestinationTopic.Properties dltProperties) {
 		assertThat(dltProperties.suffix()).isEqualTo(dltSuffix);
 		assertThat(dltProperties.isDltTopic()).isTrue();
+		assertThat(dltProperties.isRetryTopic()).isFalse();
 		DestinationTopic dltTopic = new DestinationTopic("mainTopic", dltProperties);
 		assertThat(dltTopic.getDestinationDelay()).isEqualTo(0);
 		assertThat(dltTopic.shouldRetryOn(0, new IllegalArgumentException())).isFalse();
@@ -144,6 +146,7 @@ void shouldCreateTwoRetryPropertiesForMultipleBackoffValues() {
 		DestinationTopic.Properties firstRetryProperties = propertiesList.get(1);
 		assertThat(firstRetryProperties.suffix()).isEqualTo(retryTopicSuffix + "-1000");
 		assertThat(firstRetryProperties.isDltTopic()).isFalse();
+		assertThat(firstRetryProperties.isRetryTopic()).isTrue();
 		DestinationTopic firstRetryDestinationTopic = destinationTopicList.get(1);
 		assertThat(firstRetryDestinationTopic.getDestinationDelay()).isEqualTo(1000);
 		assertThat(firstRetryDestinationTopic.getDestinationPartitions()).isEqualTo(numPartitions);
@@ -154,6 +157,7 @@ void shouldCreateTwoRetryPropertiesForMultipleBackoffValues() {
 		DestinationTopic.Properties secondRetryProperties = propertiesList.get(2);
 		assertThat(secondRetryProperties.suffix()).isEqualTo(retryTopicSuffix + "-2000");
 		assertThat(secondRetryProperties.isDltTopic()).isFalse();
+		assertThat(secondRetryProperties.isRetryTopic()).isTrue();
 		DestinationTopic secondRetryDestinationTopic = destinationTopicList.get(2);
 		assertThat(secondRetryDestinationTopic.getDestinationDelay()).isEqualTo(2000);
 		assertThat(secondRetryDestinationTopic.getDestinationPartitions()).isEqualTo(numPartitions);
@@ -219,6 +223,7 @@ void shouldCreateOneRetryPropertyForFixedBackoffWithSingleTopicStrategy() {
 
 		DestinationTopic.Properties firstRetryProperties = propertiesList.get(1);
 		assertThat(firstRetryProperties.suffix()).isEqualTo(retryTopicSuffix);
+		assertThat(firstRetryProperties.isRetryTopic()).isTrue();
 		DestinationTopic retryDestinationTopic = destinationTopicList.get(1);
 		assertThat(retryDestinationTopic.isSingleTopicRetry()).isTrue();
 		assertThat(retryDestinationTopic.getDestinationDelay()).isEqualTo(1000);
@@ -261,6 +266,7 @@ void shouldCreateRetryPropertiesForFixedBackoffWithMultiTopicStrategy() {
 
 		DestinationTopic.Properties firstRetryProperties = propertiesList.get(1);
 		assertThat(firstRetryProperties.suffix()).isEqualTo(retryTopicSuffix + "-0");
+		assertThat(firstRetryProperties.isRetryTopic()).isTrue();
 		DestinationTopic retryDestinationTopic = destinationTopicList.get(1);
 		assertThat(retryDestinationTopic.isSingleTopicRetry()).isFalse();
 		assertThat(retryDestinationTopic.getDestinationDelay()).isEqualTo(5000);