GH-4155: Add deleteTopics() method to KafkaAdmin

spring-kafka-docs/src/main/antora/modules/ROOT/pages/kafka/configuring-topics.adoc

@@ -73,11 +73,13 @@ The context then fails to initialize.
 NOTE: If the broker supports it (1.0.0 or higher), the admin increases the number of partitions if it is found that an existing topic has fewer partitions than the `NewTopic.numPartitions`.
 
 Starting with version 2.7, the `KafkaAdmin` provides methods to create and examine topics at runtime.
+Starting with version 4.0, it also provides a method to delete topics.
 
 * `createOrModifyTopics`
 * `describeTopics`
+* `deleteTopics` (since 4.0)
 
-For more advanced features, you can use the `AdminClient` directly.
+For more advanced administrative features, you can use the `AdminClient` directly.
 The following example shows how to do so:
 
 [source, java]

spring-kafka/src/main/java/org/springframework/kafka/core/KafkaAdmin.java

@@ -81,6 +81,7 @@
  * @author Anders Swanson
  * @author Omer Celik
  * @author Choi Wang Gyu
+ * @author Go Beom Jun
  *
  * @since 1.3
  */
@@ -391,6 +392,35 @@ public Map<String, TopicDescription> describeTopics(String... topicNames) {
 		}
 	}
 
+	/**
+	 * Delete topics from the Kafka cluster.
+	 * @param topicNames the topic names to delete.
+	 * @throws KafkaException if the operation fails.
+	 * @since 4.0
+	 */
+	@Override
+	public void deleteTopics(String... topicNames) {
+		if (topicNames.length == 0) {
+			return;
+		}
+		try (Admin admin = createAdmin()) {
+			admin.deleteTopics(Arrays.asList(topicNames))
+					.all()
+					.get(this.operationTimeout, TimeUnit.SECONDS);
+			LOGGER.debug(() -> "Deleted topics: " + Arrays.toString(topicNames));
+		}
+		catch (InterruptedException ex) {
+			Thread.currentThread().interrupt();
+			throw new KafkaException("Interrupted while deleting topics", ex);
+		}
+		catch (TimeoutException ex) {
+			throw new KafkaException("Timed out waiting to delete topics", ex);
+		}
+		catch (ExecutionException ex) {
+			throw new KafkaException("Failed to delete topics", ex.getCause());
+		}
+	}
+
 	/**
 	 * Creates a new {@link Admin} client instance using the {@link AdminClient} class.
 	 * @return the new {@link Admin} client instance.

spring-kafka/src/main/java/org/springframework/kafka/core/KafkaAdminOperations.java

@@ -50,6 +50,13 @@ public interface KafkaAdminOperations {
 	 */
 	Map<String, TopicDescription> describeTopics(String... topicNames);
 
+	/**
+	 * Delete topics from the Kafka cluster.
+	 * @param topicNames the topic names to delete.
+	 * @since 4.0
+	 */
+	void deleteTopics(String... topicNames);
+
 	/**
 	 * Return the cluster id, if available.
 	 * @return the describe cluster id.

spring-kafka/src/test/java/org/springframework/kafka/core/KafkaAdminTests.java

@@ -339,6 +339,65 @@ void getAdminConfigWithApplicationNameAsClientId() {
 		assertThat(kafkaAdmin.getAdminConfig()).containsOnly(Map.entry(AdminClientConfig.CLIENT_ID_CONFIG, "appname-admin-0"));
 	}
 
+	@Test
+	void testDeleteTopics() {
+		NewTopic testTopic1 = TopicBuilder.name("test-delete-1")
+				.partitions(1)
+				.replicas(1)
+				.build();
+		NewTopic testTopic2 = TopicBuilder.name("test-delete-2")
+				.partitions(1)
+				.replicas(1)
+				.build();
+
+		this.admin.createOrModifyTopics(testTopic1, testTopic2);
+
+		await().atMost(10, TimeUnit.SECONDS).until(() -> {
+			try {
+				Map<String, TopicDescription> topics =
+						this.admin.describeTopics("test-delete-1", "test-delete-2");
+				return topics.size() == 2;
+			}
+			catch (Exception e) {
+				return false;
+			}
+		});
+
+		Map<String, TopicDescription> beforeDelete = this.admin.describeTopics("test-delete-1", "test-delete-2");
+		assertThat(beforeDelete).hasSize(2);
+		assertThat(beforeDelete).containsKeys("test-delete-1", "test-delete-2");
+
+		this.admin.deleteTopics("test-delete-1", "test-delete-2");
+
+		await().atMost(10, TimeUnit.SECONDS).until(() -> {
+			try (AdminClient adminClient = AdminClient.create(this.admin.getConfigurationProperties())) {
+				DescribeTopicsResult result = adminClient.describeTopics(Arrays.asList("test-delete-1", "test-delete-2"));
+				try {
+					result.allTopicNames().get(5, TimeUnit.SECONDS);
+					return false;
+				}
+				catch (ExecutionException ex) {
+					return ex.getCause() instanceof UnknownTopicOrPartitionException;
+				}
+			}
+			catch (InterruptedException | TimeoutException e) {
+				return false;
+			}
+		});
+	}
+
+	@Test
+	void testDeleteNonExistentTopic() {
+		assertThat(org.assertj.core.api.Assertions.catchThrowable(() ->
+				this.admin.deleteTopics("non-existent-topic-12345")
+		)).isInstanceOf(org.springframework.kafka.KafkaException.class);
+	}
+
+	@Test
+	void testDeleteTopicsWithEmptyArray() {
+		this.admin.deleteTopics();
+	}
+
 	@Configuration
 	public static class Config {