GH-4871: Parse IPv6 application.server host info

spring-kafka/src/main/java/org/springframework/kafka/streams/KafkaStreamsInteractiveQueryService.java

@@ -31,7 +31,6 @@
 import org.springframework.core.retry.RetryTemplate;
 import org.springframework.kafka.config.StreamsBuilderFactoryBean;
 import org.springframework.util.Assert;
-import org.springframework.util.StringUtils;
 
 /**
  * Provide a wrapper API around the interactive query stores in Kafka Streams.
@@ -40,6 +39,7 @@
  *
  * @author Soby Chacko
  * @author Stephane Nicoll
+ * @author Yingzi Zhang
  *
  * @since 3.2
  */
@@ -110,22 +110,23 @@ private void populateKafkaStreams() {
 
 	/**
 	 * Retrieve the current {@link HostInfo} where this Kafka Streams application is running on.
-	 * This {link @HostInfo} is different from the Kafka `bootstrap.server` property and is based on
+	 * This {@link HostInfo} is different from the Kafka `bootstrap.server` property and is based on
 	 * the Kafka Streams configuration property `application.server` where user-defined REST
 	 * endpoints can be invoked per each Kafka Streams application instance.
 	 * If this property - `application.server` - is not available from the end-user application, then null is returned.
+	 * The value is parsed with {@link HostInfo#buildFromEndpoint(String)}, the same as Kafka Streams does,
+	 * so IPv6 addresses such as {@code [::1]:8080} are supported.
 	 * @return the current {@link HostInfo}
+	 * @throws org.apache.kafka.common.config.ConfigException if `application.server` is not in the
+	 * {@code host:port} format
 	 */
 	@Nullable
 	public HostInfo getCurrentKafkaStreamsApplicationHostInfo() {
 		Properties streamsConfiguration = this.streamsBuilderFactoryBean
 				.getStreamsConfiguration();
 		if (streamsConfiguration != null && streamsConfiguration.containsKey("application.server")) {
 			String applicationServer = (String) streamsConfiguration.get("application.server");
-			String[] appServerComponents = StringUtils.split(applicationServer, ":");
-			if (appServerComponents != null) {
-				return new HostInfo(appServerComponents[0], Integer.parseInt(appServerComponents[1]));
-			}
+			return HostInfo.buildFromEndpoint(applicationServer);
 		}
 		return null;
 	}

spring-kafka/src/test/java/org/springframework/kafka/streams/KafkaStreamsInteractiveQueryServiceTests.java

@@ -196,6 +196,17 @@ void currentHostInfoWithNoProperties() {
 		assertThat(currentKafkaStreamsApplicationHostInfo).isNull();
 	}
 
+	@Test
+	void currentHostInfoWithIpv6ApplicationServer() {
+		StreamsBuilderFactoryBean sbfb = new StreamsBuilderFactoryBean(new KafkaStreamsConfiguration(
+				Map.of(StreamsConfig.APPLICATION_ID_CONFIG, "iqs-ipv6",
+						StreamsConfig.APPLICATION_SERVER_CONFIG, "[::1]:8080")));
+		sbfb.setAutoStartup(false);
+		KafkaStreamsInteractiveQueryService iqs = new KafkaStreamsInteractiveQueryService(sbfb);
+		HostInfo currentKafkaStreamsApplicationHostInfo = iqs.getCurrentKafkaStreamsApplicationHostInfo();
+		assertThat(currentKafkaStreamsApplicationHostInfo).isEqualTo(new HostInfo("::1", 8080));
+	}
+
 	@Test
 	void hostInfoForKeyAndStore() throws Exception {
 		ensureKafkaStreamsProcessorIsUpAndRunning();