Add support for configuring Pulsar client IO and listener threads

Add configuration properties that allow users to configure number
of IO threads and listener threads used by the Pulsar client.

See gh-42052

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarProperties.java

@@ -44,6 +44,7 @@
  * @author Chris Bono
  * @author Phillip Webb
  * @author Swamy Mavuri
+ * @author Vedran Pavic
  * @since 3.2.0
  */
 @ConfigurationProperties("spring.pulsar")
@@ -136,6 +137,11 @@ public static class Client {
 		 */
 		private final Authentication authentication = new Authentication();
 
+		/**
+		 * Thread related configuration.
+		 */
+		private final Threads threads = new Threads();
+
 		/**
 		 * Failover settings.
 		 */
@@ -177,6 +183,10 @@ public Authentication getAuthentication() {
 			return this.authentication;
 		}
 
+		public Threads getThreads() {
+			return this.threads;
+		}
+
 		public Failover getFailover() {
 			return this.failover;
 		}
@@ -959,6 +969,36 @@ public void setParam(Map<String, String> param) {
 
 	}
 
+	public static class Threads {
+
+		/**
+		 * Number of threads to be used for handling connections to brokers.
+		 */
+		private Integer io;
+
+		/**
+		 * Number of threads to be used for message listeners.
+		 */
+		private Integer listener;
+
+		public Integer getIo() {
+			return this.io;
+		}
+
+		public void setIo(Integer io) {
+			this.io = io;
+		}
+
+		public Integer getListener() {
+			return this.listener;
+		}
+
+		public void setListener(Integer listener) {
+			this.listener = listener;
+		}
+
+	}
+
 	public static class Failover {
 
 		/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapper.java

@@ -50,6 +50,7 @@
  * @author Chris Bono
  * @author Phillip Webb
  * @author Swamy Mavuri
+ * @author Vedran Pavic
  */
 final class PulsarPropertiesMapper {
 
@@ -68,6 +69,8 @@ void customizeClientBuilder(ClientBuilder clientBuilder, PulsarConnectionDetails
 		map.from(properties::getConnectionTimeout).to(timeoutProperty(clientBuilder::connectionTimeout));
 		map.from(properties::getOperationTimeout).to(timeoutProperty(clientBuilder::operationTimeout));
 		map.from(properties::getLookupTimeout).to(timeoutProperty(clientBuilder::lookupTimeout));
+		map.from(properties.getThreads()::getIo).to(clientBuilder::ioThreads);
+		map.from(properties.getThreads()::getListener).to(clientBuilder::listenerThreads);
 		map.from(this.properties.getTransaction()::isEnabled).whenTrue().to(clientBuilder::enableTransaction);
 		customizeAuthentication(properties.getAuthentication(), clientBuilder::authentication);
 		customizeServiceUrlProviderBuilder(clientBuilder::serviceUrl, clientBuilder::serviceUrlProvider, properties,

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesMapperTests.java

@@ -59,6 +59,7 @@
  * @author Chris Bono
  * @author Phillip Webb
  * @author Swamy Mavuri
+ * @author Vedran Pavic
  */
 class PulsarPropertiesMapperTests {
 
@@ -69,13 +70,17 @@ void customizeClientBuilderWhenHasNoAuthentication() {
 		properties.getClient().setConnectionTimeout(Duration.ofSeconds(1));
 		properties.getClient().setOperationTimeout(Duration.ofSeconds(2));
 		properties.getClient().setLookupTimeout(Duration.ofSeconds(3));
+		properties.getClient().getThreads().setIo(3);
+		properties.getClient().getThreads().setListener(10);
 		ClientBuilder builder = mock(ClientBuilder.class);
 		new PulsarPropertiesMapper(properties).customizeClientBuilder(builder,
 				new PropertiesPulsarConnectionDetails(properties));
 		then(builder).should().serviceUrl("https://example.com");
 		then(builder).should().connectionTimeout(1000, TimeUnit.MILLISECONDS);
 		then(builder).should().operationTimeout(2000, TimeUnit.MILLISECONDS);
 		then(builder).should().lookupTimeout(3000, TimeUnit.MILLISECONDS);
+		then(builder).should().ioThreads(3);
+		then(builder).should().listenerThreads(10);
 	}
 
 	@Test

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/pulsar/PulsarPropertiesTests.java

@@ -54,6 +54,7 @@
  * @author Soby Chacko
  * @author Phillip Webb
  * @author Swamy Mavuri
+ * @author Vedran Pavic
  */
 class PulsarPropertiesTests {
 
@@ -88,6 +89,16 @@ void bindAuthentication() {
 			assertThat(properties.getAuthentication().getParam()).containsEntry("token", "1234");
 		}
 
+		@Test
+		void bindThread() {
+			Map<String, String> map = new HashMap<>();
+			map.put("spring.pulsar.client.threads.io", "3");
+			map.put("spring.pulsar.client.threads.listener", "10");
+			PulsarProperties.Client properties = bindProperties(map).getClient();
+			assertThat(properties.getThreads().getIo()).isEqualTo(3);
+			assertThat(properties.getThreads().getListener()).isEqualTo(10);
+		}
+
 		@Test
 		void bindFailover() {
 			Map<String, String> map = new HashMap<>();