Add nullability annotations to module/spring-boot-amqp

See gh-46587

documentation/spring-boot-docs/src/main/kotlin/org/springframework/boot/docs/messaging/amqp/receiving/custom/MyRabbitConfiguration.kt

@@ -17,6 +17,7 @@
 package org.springframework.boot.docs.messaging.amqp.receiving.custom
 
 import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory
+import org.springframework.amqp.rabbit.connection.CachingConnectionFactory
 import org.springframework.amqp.rabbit.connection.ConnectionFactory
 import org.springframework.boot.amqp.autoconfigure.SimpleRabbitListenerContainerFactoryConfigurer
 import org.springframework.context.annotation.Bean
@@ -34,8 +35,8 @@ class MyRabbitConfiguration {
 		return factory
 	}
 
-	fun getCustomConnectionFactory() : ConnectionFactory? {
-		return /**/ null
+	fun getCustomConnectionFactory() : ConnectionFactory {
+		return /**/ CachingConnectionFactory()
 	}
 
 }

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/AbstractConnectionFactoryConfigurer.java

@@ -18,6 +18,8 @@ package org.springframework.boot.amqp.autoconfigure;
 
 import java.util.stream.Collectors;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.rabbit.connection.AbstractConnectionFactory;
 import org.springframework.amqp.rabbit.connection.ConnectionNameStrategy;
 import org.springframework.boot.context.properties.PropertyMapper;
@@ -37,7 +39,7 @@ public abstract class AbstractConnectionFactoryConfigurer<T extends AbstractConn
 
 	private final RabbitProperties rabbitProperties;
 
-	private ConnectionNameStrategy connectionNameStrategy;
+	private @Nullable ConnectionNameStrategy connectionNameStrategy;
 
 	private final RabbitConnectionDetails connectionDetails;
 
@@ -65,11 +67,11 @@ public abstract class AbstractConnectionFactoryConfigurer<T extends AbstractConn
 		this.connectionDetails = connectionDetails;
 	}
 
-	protected final ConnectionNameStrategy getConnectionNameStrategy() {
+	protected final @Nullable ConnectionNameStrategy getConnectionNameStrategy() {
 		return this.connectionNameStrategy;
 	}
 
-	public final void setConnectionNameStrategy(ConnectionNameStrategy connectionNameStrategy) {
+	public final void setConnectionNameStrategy(@Nullable ConnectionNameStrategy connectionNameStrategy) {
 		this.connectionNameStrategy = connectionNameStrategy;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/AbstractRabbitListenerContainerFactoryConfigurer.java

@@ -19,6 +19,8 @@ package org.springframework.boot.amqp.autoconfigure;
 import java.util.List;
 import java.util.concurrent.Executor;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.rabbit.config.AbstractRabbitListenerContainerFactory;
 import org.springframework.amqp.rabbit.config.RetryInterceptorBuilder;
 import org.springframework.amqp.rabbit.connection.ConnectionFactory;
@@ -40,15 +42,15 @@ import org.springframework.util.Assert;
  */
 public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends AbstractRabbitListenerContainerFactory<?>> {
 
-	private MessageConverter messageConverter;
+	private @Nullable MessageConverter messageConverter;
 
-	private MessageRecoverer messageRecoverer;
+	private @Nullable MessageRecoverer messageRecoverer;
 
-	private List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers;
+	private @Nullable List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers;
 
 	private final RabbitProperties rabbitProperties;
 
-	private Executor taskExecutor;
+	private @Nullable Executor taskExecutor;
 
 	/**
 	 * Creates a new configurer that will use the given {@code rabbitProperties}.
@@ -63,7 +65,7 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 	 * converter should be used.
 	 * @param messageConverter the {@link MessageConverter}
 	 */
-	protected void setMessageConverter(MessageConverter messageConverter) {
+	protected void setMessageConverter(@Nullable MessageConverter messageConverter) {
 		this.messageConverter = messageConverter;
 	}
 
@@ -71,7 +73,7 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 	 * Set the {@link MessageRecoverer} to use or {@code null} to rely on the default.
 	 * @param messageRecoverer the {@link MessageRecoverer}
 	 */
-	protected void setMessageRecoverer(MessageRecoverer messageRecoverer) {
+	protected void setMessageRecoverer(@Nullable MessageRecoverer messageRecoverer) {
 		this.messageRecoverer = messageRecoverer;
 	}
 
@@ -79,7 +81,7 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 	 * Set the {@link RabbitRetryTemplateCustomizer} instances to use.
 	 * @param retryTemplateCustomizers the retry template customizers
 	 */
-	protected void setRetryTemplateCustomizers(List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers) {
+	protected void setRetryTemplateCustomizers(@Nullable List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers) {
 		this.retryTemplateCustomizers = retryTemplateCustomizers;
 	}
 
@@ -87,7 +89,7 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 	 * Set the task executor to use.
 	 * @param taskExecutor the task executor
 	 */
-	public void setTaskExecutor(Executor taskExecutor) {
+	public void setTaskExecutor(@Nullable Executor taskExecutor) {
 		this.taskExecutor = taskExecutor;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/PropertiesRabbitConnectionDetails.java

@@ -19,6 +19,8 @@ package org.springframework.boot.amqp.autoconfigure;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.amqp.autoconfigure.RabbitProperties.Ssl;
 import org.springframework.boot.ssl.SslBundle;
 import org.springframework.boot.ssl.SslBundles;
@@ -36,9 +38,9 @@ class PropertiesRabbitConnectionDetails implements RabbitConnectionDetails {
 
 	private final RabbitProperties properties;
 
-	private final SslBundles sslBundles;
+	private final @Nullable SslBundles sslBundles;
 
-	PropertiesRabbitConnectionDetails(RabbitProperties properties, SslBundles sslBundles) {
+	PropertiesRabbitConnectionDetails(RabbitProperties properties, @Nullable SslBundles sslBundles) {
 		this.properties = properties;
 		this.sslBundles = sslBundles;
 	}
@@ -49,12 +51,12 @@ class PropertiesRabbitConnectionDetails implements RabbitConnectionDetails {
 	}
 
 	@Override
-	public String getPassword() {
+	public @Nullable String getPassword() {
 		return this.properties.determinePassword();
 	}
 
 	@Override
-	public String getVirtualHost() {
+	public @Nullable String getVirtualHost() {
 		return this.properties.determineVirtualHost();
 	}
 
@@ -71,7 +73,7 @@ class PropertiesRabbitConnectionDetails implements RabbitConnectionDetails {
 	}
 
 	@Override
-	public SslBundle getSslBundle() {
+	public @Nullable SslBundle getSslBundle() {
 		Ssl ssl = this.properties.getSsl();
 		if (!ssl.determineEnabled()) {
 			return null;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitConnectionDetails.java

@@ -18,6 +18,8 @@ package org.springframework.boot.amqp.autoconfigure;
 
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.autoconfigure.service.connection.ConnectionDetails;
 import org.springframework.boot.ssl.SslBundle;
 import org.springframework.util.Assert;
@@ -36,7 +38,7 @@ public interface RabbitConnectionDetails extends ConnectionDetails {
 	 * Login user to authenticate to the broker.
 	 * @return the login user to authenticate to the broker or {@code null}
 	 */
-	default String getUsername() {
+	default @Nullable String getUsername() {
 		return null;
 	}
 
@@ -44,7 +46,7 @@ public interface RabbitConnectionDetails extends ConnectionDetails {
 	 * Login to authenticate against the broker.
 	 * @return the login to authenticate against the broker or {@code null}
 	 */
-	default String getPassword() {
+	default @Nullable String getPassword() {
 		return null;
 	}
 
@@ -52,7 +54,7 @@ public interface RabbitConnectionDetails extends ConnectionDetails {
 	 * Virtual host to use when connecting to the broker.
 	 * @return the virtual host to use when connecting to the broker or {@code null}
 	 */
-	default String getVirtualHost() {
+	default @Nullable String getVirtualHost() {
 		return null;
 	}
 
@@ -78,7 +80,7 @@ public interface RabbitConnectionDetails extends ConnectionDetails {
 	 * SSL bundle to use.
 	 * @return the SSL bundle to use
 	 */
-	default SslBundle getSslBundle() {
+	default @Nullable SslBundle getSslBundle() {
 		return null;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitConnectionFactoryBeanConfigurer.java

@@ -20,6 +20,7 @@ import java.time.Duration;
 
 import com.rabbitmq.client.impl.CredentialsProvider;
 import com.rabbitmq.client.impl.CredentialsRefreshService;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.amqp.rabbit.connection.RabbitConnectionFactoryBean;
 import org.springframework.boot.amqp.autoconfigure.RabbitConnectionDetails.Address;
@@ -53,9 +54,9 @@ public class RabbitConnectionFactoryBeanConfigurer {
 
 	private final RabbitConnectionDetails connectionDetails;
 
-	private CredentialsProvider credentialsProvider;
+	private @Nullable CredentialsProvider credentialsProvider;
 
-	private CredentialsRefreshService credentialsRefreshService;
+	private @Nullable CredentialsRefreshService credentialsRefreshService;
 
 	/**
 	 * Creates a new configurer that will use the given {@code resourceLoader} and
@@ -90,7 +91,7 @@ public class RabbitConnectionFactoryBeanConfigurer {
 	 * @param sslBundles the SSL bundles
 	 */
 	public RabbitConnectionFactoryBeanConfigurer(ResourceLoader resourceLoader, RabbitProperties properties,
-			RabbitConnectionDetails connectionDetails, SslBundles sslBundles) {
+			RabbitConnectionDetails connectionDetails, @Nullable SslBundles sslBundles) {
 		Assert.notNull(resourceLoader, "'resourceLoader' must not be null");
 		Assert.notNull(properties, "'properties' must not be null");
 		Assert.notNull(connectionDetails, "'connectionDetails' must not be null");
@@ -99,11 +100,11 @@ public class RabbitConnectionFactoryBeanConfigurer {
 		this.connectionDetails = connectionDetails;
 	}
 
-	public void setCredentialsProvider(CredentialsProvider credentialsProvider) {
+	public void setCredentialsProvider(@Nullable CredentialsProvider credentialsProvider) {
 		this.credentialsProvider = credentialsProvider;
 	}
 
-	public void setCredentialsRefreshService(CredentialsRefreshService credentialsRefreshService) {
+	public void setCredentialsRefreshService(@Nullable CredentialsRefreshService credentialsRefreshService) {
 		this.credentialsRefreshService = credentialsRefreshService;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitProperties.java

@@ -21,6 +21,8 @@ import java.time.temporal.ChronoUnit;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.core.AcknowledgeMode;
 import org.springframework.amqp.rabbit.connection.AbstractConnectionFactory.AddressShuffleMode;
 import org.springframework.amqp.rabbit.connection.CachingConnectionFactory.CacheMode;
@@ -68,7 +70,7 @@ public class RabbitProperties {
 	 * RabbitMQ port. Ignored if an address is set. Default to 5672, or 5671 if SSL is
 	 * enabled.
 	 */
-	private Integer port;
+	private @Nullable Integer port;
 
 	/**
 	 * Login user to authenticate to the broker.
@@ -88,13 +90,13 @@ public class RabbitProperties {
 	/**
 	 * Virtual host to use when connecting to the broker.
 	 */
-	private String virtualHost;
+	private @Nullable String virtualHost;
 
 	/**
 	 * List of addresses to which the client should connect. When set, the host and port
 	 * are ignored.
 	 */
-	private List<String> addresses;
+	private @Nullable List<String> addresses;
 
 	/**
 	 * Mode used to shuffle configured addresses.
@@ -106,7 +108,7 @@ public class RabbitProperties {
 	 * seconds will be used.
 	 */
 	@DurationUnit(ChronoUnit.SECONDS)
-	private Duration requestedHeartbeat;
+	private @Nullable Duration requestedHeartbeat;
 
 	/**
 	 * Number of channels per connection requested by the client. Use 0 for unlimited.
@@ -121,12 +123,12 @@ public class RabbitProperties {
 	/**
 	 * Type of publisher confirms to use.
 	 */
-	private ConfirmType publisherConfirmType;
+	private @Nullable ConfirmType publisherConfirmType;
 
 	/**
 	 * Connection timeout. Set it to zero to wait forever.
 	 */
-	private Duration connectionTimeout;
+	private @Nullable Duration connectionTimeout;
 
 	/**
 	 * Continuation timeout for RPC calls in channels. Set it to zero to wait forever.
@@ -152,7 +154,7 @@ public class RabbitProperties {
 
 	private final Stream stream = new Stream();
 
-	private List<Address> parsedAddresses;
+	private @Nullable List<Address> parsedAddresses;
 
 	public String getHost() {
 		return this.host;
@@ -176,7 +178,7 @@ public class RabbitProperties {
 		this.host = host;
 	}
 
-	public Integer getPort() {
+	public @Nullable Integer getPort() {
 		return this.port;
 	}
 
@@ -198,11 +200,11 @@ public class RabbitProperties {
 		return this.parsedAddresses.get(0).port;
 	}
 
-	public void setPort(Integer port) {
+	public void setPort(@Nullable Integer port) {
 		this.port = port;
 	}
 
-	public List<String> getAddresses() {
+	public @Nullable List<String> getAddresses() {
 		return this.addresses;
 	}
 
@@ -273,7 +275,7 @@ public class RabbitProperties {
 	 * @see #setAddresses(List)
 	 * @see #getPassword()
 	 */
-	public String determinePassword() {
+	public @Nullable String determinePassword() {
 		if (CollectionUtils.isEmpty(this.parsedAddresses)) {
 			return getPassword();
 		}
@@ -289,7 +291,7 @@ public class RabbitProperties {
 		return this.ssl;
 	}
 
-	public String getVirtualHost() {
+	public @Nullable String getVirtualHost() {
 		return this.virtualHost;
 	}
 
@@ -300,7 +302,7 @@ public class RabbitProperties {
 	 * @see #setAddresses(List)
 	 * @see #getVirtualHost()
 	 */
-	public String determineVirtualHost() {
+	public @Nullable String determineVirtualHost() {
 		if (CollectionUtils.isEmpty(this.parsedAddresses)) {
 			return getVirtualHost();
 		}
@@ -308,7 +310,7 @@ public class RabbitProperties {
 		return (address.virtualHost != null) ? address.virtualHost : getVirtualHost();
 	}
 
-	public void setVirtualHost(String virtualHost) {
+	public void setVirtualHost(@Nullable String virtualHost) {
 		this.virtualHost = StringUtils.hasText(virtualHost) ? virtualHost : "/";
 	}
 
@@ -320,11 +322,11 @@ public class RabbitProperties {
 		this.addressShuffleMode = addressShuffleMode;
 	}
 
-	public Duration getRequestedHeartbeat() {
+	public @Nullable Duration getRequestedHeartbeat() {
 		return this.requestedHeartbeat;
 	}
 
-	public void setRequestedHeartbeat(Duration requestedHeartbeat) {
+	public void setRequestedHeartbeat(@Nullable Duration requestedHeartbeat) {
 		this.requestedHeartbeat = requestedHeartbeat;
 	}
 
@@ -344,19 +346,19 @@ public class RabbitProperties {
 		this.publisherReturns = publisherReturns;
 	}
 
-	public Duration getConnectionTimeout() {
+	public @Nullable Duration getConnectionTimeout() {
 		return this.connectionTimeout;
 	}
 
-	public void setPublisherConfirmType(ConfirmType publisherConfirmType) {
+	public void setPublisherConfirmType(@Nullable ConfirmType publisherConfirmType) {
 		this.publisherConfirmType = publisherConfirmType;
 	}
 
-	public ConfirmType getPublisherConfirmType() {
+	public @Nullable ConfirmType getPublisherConfirmType() {
 		return this.publisherConfirmType;
 	}
 
-	public void setConnectionTimeout(Duration connectionTimeout) {
+	public void setConnectionTimeout(@Nullable Duration connectionTimeout) {
 		this.connectionTimeout = connectionTimeout;
 	}
 
@@ -400,17 +402,17 @@ public class RabbitProperties {
 		 * Whether to enable SSL support. Determined automatically if an address is
 		 * provided with the protocol (amqp:// vs. amqps://).
 		 */
-		private Boolean enabled;
+		private @Nullable Boolean enabled;
 
 		/**
 		 * SSL bundle name.
 		 */
-		private String bundle;
+		private @Nullable String bundle;
 
 		/**
 		 * Path to the key store that holds the SSL certificate.
 		 */
-		private String keyStore;
+		private @Nullable String keyStore;
 
 		/**
 		 * Key store type.
@@ -420,7 +422,7 @@ public class RabbitProperties {
 		/**
 		 * Password used to access the key store.
 		 */
-		private String keyStorePassword;
+		private @Nullable String keyStorePassword;
 
 		/**
 		 * Key store algorithm.
@@ -430,7 +432,7 @@ public class RabbitProperties {
 		/**
 		 * Trust store that holds SSL certificates.
 		 */
-		private String trustStore;
+		private @Nullable String trustStore;
 
 		/**
 		 * Trust store type.
@@ -440,7 +442,7 @@ public class RabbitProperties {
 		/**
 		 * Password used to access the trust store.
 		 */
-		private String trustStorePassword;
+		private @Nullable String trustStorePassword;
 
 		/**
 		 * Trust store algorithm.
@@ -450,7 +452,7 @@ public class RabbitProperties {
 		/**
 		 * SSL algorithm to use. By default, configured by the Rabbit client library.
 		 */
-		private String algorithm;
+		private @Nullable String algorithm;
 
 		/**
 		 * Whether to enable server side certificate validation.
@@ -462,7 +464,7 @@ public class RabbitProperties {
 		 */
 		private boolean verifyHostname = true;
 
-		public Boolean getEnabled() {
+		public @Nullable Boolean getEnabled() {
 			return this.enabled;
 		}
 
@@ -482,23 +484,23 @@ public class RabbitProperties {
 			return address.determineSslEnabled(defaultEnabled);
 		}
 
-		public void setEnabled(Boolean enabled) {
+		public void setEnabled(@Nullable Boolean enabled) {
 			this.enabled = enabled;
 		}
 
-		public String getBundle() {
+		public @Nullable String getBundle() {
 			return this.bundle;
 		}
 
-		public void setBundle(String bundle) {
+		public void setBundle(@Nullable String bundle) {
 			this.bundle = bundle;
 		}
 
-		public String getKeyStore() {
+		public @Nullable String getKeyStore() {
 			return this.keyStore;
 		}
 
-		public void setKeyStore(String keyStore) {
+		public void setKeyStore(@Nullable String keyStore) {
 			this.keyStore = keyStore;
 		}
 
@@ -510,11 +512,11 @@ public class RabbitProperties {
 			this.keyStoreType = keyStoreType;
 		}
 
-		public String getKeyStorePassword() {
+		public @Nullable String getKeyStorePassword() {
 			return this.keyStorePassword;
 		}
 
-		public void setKeyStorePassword(String keyStorePassword) {
+		public void setKeyStorePassword(@Nullable String keyStorePassword) {
 			this.keyStorePassword = keyStorePassword;
 		}
 
@@ -526,11 +528,11 @@ public class RabbitProperties {
 			this.keyStoreAlgorithm = keyStoreAlgorithm;
 		}
 
-		public String getTrustStore() {
+		public @Nullable String getTrustStore() {
 			return this.trustStore;
 		}
 
-		public void setTrustStore(String trustStore) {
+		public void setTrustStore(@Nullable String trustStore) {
 			this.trustStore = trustStore;
 		}
 
@@ -542,11 +544,11 @@ public class RabbitProperties {
 			this.trustStoreType = trustStoreType;
 		}
 
-		public String getTrustStorePassword() {
+		public @Nullable String getTrustStorePassword() {
 			return this.trustStorePassword;
 		}
 
-		public void setTrustStorePassword(String trustStorePassword) {
+		public void setTrustStorePassword(@Nullable String trustStorePassword) {
 			this.trustStorePassword = trustStorePassword;
 		}
 
@@ -558,11 +560,11 @@ public class RabbitProperties {
 			this.trustStoreAlgorithm = trustStoreAlgorithm;
 		}
 
-		public String getAlgorithm() {
+		public @Nullable String getAlgorithm() {
 			return this.algorithm;
 		}
 
-		public void setAlgorithm(String sslAlgorithm) {
+		public void setAlgorithm(@Nullable String sslAlgorithm) {
 			this.algorithm = sslAlgorithm;
 		}
 
@@ -604,27 +606,27 @@ public class RabbitProperties {
 			 * Number of channels to retain in the cache. When "check-timeout" > 0, max
 			 * channels per connection.
 			 */
-			private Integer size;
+			private @Nullable Integer size;
 
 			/**
 			 * Duration to wait to obtain a channel if the cache size has been reached. If
 			 * 0, always create a new channel.
 			 */
-			private Duration checkoutTimeout;
+			private @Nullable Duration checkoutTimeout;
 
-			public Integer getSize() {
+			public @Nullable Integer getSize() {
 				return this.size;
 			}
 
-			public void setSize(Integer size) {
+			public void setSize(@Nullable Integer size) {
 				this.size = size;
 			}
 
-			public Duration getCheckoutTimeout() {
+			public @Nullable Duration getCheckoutTimeout() {
 				return this.checkoutTimeout;
 			}
 
-			public void setCheckoutTimeout(Duration checkoutTimeout) {
+			public void setCheckoutTimeout(@Nullable Duration checkoutTimeout) {
 				this.checkoutTimeout = checkoutTimeout;
 			}
 
@@ -640,7 +642,7 @@ public class RabbitProperties {
 			/**
 			 * Number of connections to cache. Only applies when mode is CONNECTION.
 			 */
-			private Integer size;
+			private @Nullable Integer size;
 
 			public CacheMode getMode() {
 				return this.mode;
@@ -650,11 +652,11 @@ public class RabbitProperties {
 				this.mode = mode;
 			}
 
-			public Integer getSize() {
+			public @Nullable Integer getSize() {
 				return this.size;
 			}
 
-			public void setSize(Integer size) {
+			public void setSize(@Nullable Integer size) {
 				this.size = size;
 			}
 
@@ -744,23 +746,23 @@ public class RabbitProperties {
 		/**
 		 * Acknowledge mode of container.
 		 */
-		private AcknowledgeMode acknowledgeMode;
+		private @Nullable AcknowledgeMode acknowledgeMode;
 
 		/**
 		 * Maximum number of unacknowledged messages that can be outstanding at each
 		 * consumer.
 		 */
-		private Integer prefetch;
+		private @Nullable Integer prefetch;
 
 		/**
 		 * Whether rejected deliveries are re-queued by default.
 		 */
-		private Boolean defaultRequeueRejected;
+		private @Nullable Boolean defaultRequeueRejected;
 
 		/**
 		 * How often idle container events should be published.
 		 */
-		private Duration idleEventInterval;
+		private @Nullable Duration idleEventInterval;
 
 		/**
 		 * Whether the container should present batched messages as discrete messages or
@@ -787,35 +789,35 @@ public class RabbitProperties {
 			this.autoStartup = autoStartup;
 		}
 
-		public AcknowledgeMode getAcknowledgeMode() {
+		public @Nullable AcknowledgeMode getAcknowledgeMode() {
 			return this.acknowledgeMode;
 		}
 
-		public void setAcknowledgeMode(AcknowledgeMode acknowledgeMode) {
+		public void setAcknowledgeMode(@Nullable AcknowledgeMode acknowledgeMode) {
 			this.acknowledgeMode = acknowledgeMode;
 		}
 
-		public Integer getPrefetch() {
+		public @Nullable Integer getPrefetch() {
 			return this.prefetch;
 		}
 
-		public void setPrefetch(Integer prefetch) {
+		public void setPrefetch(@Nullable Integer prefetch) {
 			this.prefetch = prefetch;
 		}
 
-		public Boolean getDefaultRequeueRejected() {
+		public @Nullable Boolean getDefaultRequeueRejected() {
 			return this.defaultRequeueRejected;
 		}
 
-		public void setDefaultRequeueRejected(Boolean defaultRequeueRejected) {
+		public void setDefaultRequeueRejected(@Nullable Boolean defaultRequeueRejected) {
 			this.defaultRequeueRejected = defaultRequeueRejected;
 		}
 
-		public Duration getIdleEventInterval() {
+		public @Nullable Duration getIdleEventInterval() {
 			return this.idleEventInterval;
 		}
 
-		public void setIdleEventInterval(Duration idleEventInterval) {
+		public void setIdleEventInterval(@Nullable Duration idleEventInterval) {
 			this.idleEventInterval = idleEventInterval;
 		}
 
@@ -851,18 +853,18 @@ public class RabbitProperties {
 		/**
 		 * Minimum number of listener invoker threads.
 		 */
-		private Integer concurrency;
+		private @Nullable Integer concurrency;
 
 		/**
 		 * Maximum number of listener invoker threads.
 		 */
-		private Integer maxConcurrency;
+		private @Nullable Integer maxConcurrency;
 
 		/**
 		 * Batch size, expressed as the number of physical messages, to be used by the
 		 * container.
 		 */
-		private Integer batchSize;
+		private @Nullable Integer batchSize;
 
 		/**
 		 * Whether to fail if the queues declared by the container are not available on
@@ -879,27 +881,27 @@ public class RabbitProperties {
 		 */
 		private boolean consumerBatchEnabled;
 
-		public Integer getConcurrency() {
+		public @Nullable Integer getConcurrency() {
 			return this.concurrency;
 		}
 
-		public void setConcurrency(Integer concurrency) {
+		public void setConcurrency(@Nullable Integer concurrency) {
 			this.concurrency = concurrency;
 		}
 
-		public Integer getMaxConcurrency() {
+		public @Nullable Integer getMaxConcurrency() {
 			return this.maxConcurrency;
 		}
 
-		public void setMaxConcurrency(Integer maxConcurrency) {
+		public void setMaxConcurrency(@Nullable Integer maxConcurrency) {
 			this.maxConcurrency = maxConcurrency;
 		}
 
-		public Integer getBatchSize() {
+		public @Nullable Integer getBatchSize() {
 			return this.batchSize;
 		}
 
-		public void setBatchSize(Integer batchSize) {
+		public void setBatchSize(@Nullable Integer batchSize) {
 			this.batchSize = batchSize;
 		}
 
@@ -930,7 +932,7 @@ public class RabbitProperties {
 		/**
 		 * Number of consumers per queue.
 		 */
-		private Integer consumersPerQueue;
+		private @Nullable Integer consumersPerQueue;
 
 		/**
 		 * Whether to fail if the queues declared by the container are not available on
@@ -938,11 +940,11 @@ public class RabbitProperties {
 		 */
 		private boolean missingQueuesFatal = false;
 
-		public Integer getConsumersPerQueue() {
+		public @Nullable Integer getConsumersPerQueue() {
 			return this.consumersPerQueue;
 		}
 
-		public void setConsumersPerQueue(Integer consumersPerQueue) {
+		public void setConsumersPerQueue(@Nullable Integer consumersPerQueue) {
 			this.consumersPerQueue = consumersPerQueue;
 		}
 
@@ -982,17 +984,17 @@ public class RabbitProperties {
 		/**
 		 * Whether to enable mandatory messages.
 		 */
-		private Boolean mandatory;
+		private @Nullable Boolean mandatory;
 
 		/**
 		 * Timeout for receive() operations.
 		 */
-		private Duration receiveTimeout;
+		private @Nullable Duration receiveTimeout;
 
 		/**
 		 * Timeout for sendAndReceive() operations.
 		 */
-		private Duration replyTimeout;
+		private @Nullable Duration replyTimeout;
 
 		/**
 		 * Name of the default exchange to use for send operations.
@@ -1008,7 +1010,7 @@ public class RabbitProperties {
 		 * Name of the default queue to receive messages from when none is specified
 		 * explicitly.
 		 */
-		private String defaultReceiveQueue;
+		private @Nullable String defaultReceiveQueue;
 
 		/**
 		 * Whether to enable observation.
@@ -1018,33 +1020,33 @@ public class RabbitProperties {
 		/**
 		 * Simple patterns for allowable packages/classes for deserialization.
 		 */
-		private List<String> allowedListPatterns;
+		private @Nullable List<String> allowedListPatterns;
 
 		public Retry getRetry() {
 			return this.retry;
 		}
 
-		public Boolean getMandatory() {
+		public @Nullable Boolean getMandatory() {
 			return this.mandatory;
 		}
 
-		public void setMandatory(Boolean mandatory) {
+		public void setMandatory(@Nullable Boolean mandatory) {
 			this.mandatory = mandatory;
 		}
 
-		public Duration getReceiveTimeout() {
+		public @Nullable Duration getReceiveTimeout() {
 			return this.receiveTimeout;
 		}
 
-		public void setReceiveTimeout(Duration receiveTimeout) {
+		public void setReceiveTimeout(@Nullable Duration receiveTimeout) {
 			this.receiveTimeout = receiveTimeout;
 		}
 
-		public Duration getReplyTimeout() {
+		public @Nullable Duration getReplyTimeout() {
 			return this.replyTimeout;
 		}
 
-		public void setReplyTimeout(Duration replyTimeout) {
+		public void setReplyTimeout(@Nullable Duration replyTimeout) {
 			this.replyTimeout = replyTimeout;
 		}
 
@@ -1064,11 +1066,11 @@ public class RabbitProperties {
 			this.routingKey = routingKey;
 		}
 
-		public String getDefaultReceiveQueue() {
+		public @Nullable String getDefaultReceiveQueue() {
 			return this.defaultReceiveQueue;
 		}
 
-		public void setDefaultReceiveQueue(String defaultReceiveQueue) {
+		public void setDefaultReceiveQueue(@Nullable String defaultReceiveQueue) {
 			this.defaultReceiveQueue = defaultReceiveQueue;
 		}
 
@@ -1080,11 +1082,11 @@ public class RabbitProperties {
 			this.observationEnabled = observationEnabled;
 		}
 
-		public List<String> getAllowedListPatterns() {
+		public @Nullable List<String> getAllowedListPatterns() {
 			return this.allowedListPatterns;
 		}
 
-		public void setAllowedListPatterns(List<String> allowedListPatterns) {
+		public void setAllowedListPatterns(@Nullable List<String> allowedListPatterns) {
 			this.allowedListPatterns = allowedListPatterns;
 		}
 
@@ -1186,13 +1188,13 @@ public class RabbitProperties {
 
 		private int port;
 
-		private String username;
+		private @Nullable String username;
 
-		private String password;
+		private @Nullable String password;
 
-		private String virtualHost;
+		private @Nullable String virtualHost;
 
-		private Boolean secureConnection;
+		private @Nullable Boolean secureConnection;
 
 		private Address(String input, boolean sslEnabled) {
 			input = input.trim();
@@ -1278,24 +1280,24 @@ public class RabbitProperties {
 		 * Virtual host of a RabbitMQ instance with the Stream plugin enabled. When not
 		 * set, spring.rabbitmq.virtual-host is used.
 		 */
-		private String virtualHost;
+		private @Nullable String virtualHost;
 
 		/**
 		 * Login user to authenticate to the broker. When not set,
 		 * spring.rabbitmq.username is used.
 		 */
-		private String username;
+		private @Nullable String username;
 
 		/**
 		 * Login password to authenticate to the broker. When not set
 		 * spring.rabbitmq.password is used.
 		 */
-		private String password;
+		private @Nullable String password;
 
 		/**
 		 * Name of the stream.
 		 */
-		private String name;
+		private @Nullable String name;
 
 		public String getHost() {
 			return this.host;
@@ -1313,35 +1315,35 @@ public class RabbitProperties {
 			this.port = port;
 		}
 
-		public String getVirtualHost() {
+		public @Nullable String getVirtualHost() {
 			return this.virtualHost;
 		}
 
-		public void setVirtualHost(String virtualHost) {
+		public void setVirtualHost(@Nullable String virtualHost) {
 			this.virtualHost = virtualHost;
 		}
 
-		public String getUsername() {
+		public @Nullable String getUsername() {
 			return this.username;
 		}
 
-		public void setUsername(String username) {
+		public void setUsername(@Nullable String username) {
 			this.username = username;
 		}
 
-		public String getPassword() {
+		public @Nullable String getPassword() {
 			return this.password;
 		}
 
-		public void setPassword(String password) {
+		public void setPassword(@Nullable String password) {
 			this.password = password;
 		}
 
-		public String getName() {
+		public @Nullable String getName() {
 			return this.name;
 		}
 
-		public void setName(String name) {
+		public void setName(@Nullable String name) {
 			this.name = name;
 		}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfiguration.java

@@ -39,6 +39,7 @@ import org.springframework.rabbit.stream.producer.ProducerCustomizer;
 import org.springframework.rabbit.stream.producer.RabbitStreamOperations;
 import org.springframework.rabbit.stream.producer.RabbitStreamTemplate;
 import org.springframework.rabbit.stream.support.converter.StreamMessageConverter;
+import org.springframework.util.Assert;
 
 /**
  * Configuration for Spring RabbitMQ Stream plugin support.
@@ -93,8 +94,9 @@ class RabbitStreamConfiguration {
 	@ConditionalOnProperty(name = "spring.rabbitmq.stream.name")
 	RabbitStreamTemplate rabbitStreamTemplate(Environment rabbitStreamEnvironment, RabbitProperties properties,
 			RabbitStreamTemplateConfigurer configurer) {
-		RabbitStreamTemplate template = new RabbitStreamTemplate(rabbitStreamEnvironment,
-				properties.getStream().getName());
+		String name = properties.getStream().getName();
+		Assert.state(name != null, "'name' must not be null");
+		RabbitStreamTemplate template = new RabbitStreamTemplate(rabbitStreamEnvironment, name);
 		configurer.configure(template);
 		return template;
 	}

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamTemplateConfigurer.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.amqp.autoconfigure;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.support.converter.MessageConverter;
 import org.springframework.rabbit.stream.producer.ProducerCustomizer;
 import org.springframework.rabbit.stream.producer.RabbitStreamTemplate;
@@ -33,18 +35,18 @@ import org.springframework.rabbit.stream.support.converter.StreamMessageConverte
  */
 public class RabbitStreamTemplateConfigurer {
 
-	private MessageConverter messageConverter;
+	private @Nullable MessageConverter messageConverter;
 
-	private StreamMessageConverter streamMessageConverter;
+	private @Nullable StreamMessageConverter streamMessageConverter;
 
-	private ProducerCustomizer producerCustomizer;
+	private @Nullable ProducerCustomizer producerCustomizer;
 
 	/**
 	 * Set the {@link MessageConverter} to use or {@code null} if the out-of-the-box
 	 * converter should be used.
 	 * @param messageConverter the {@link MessageConverter}
 	 */
-	public void setMessageConverter(MessageConverter messageConverter) {
+	public void setMessageConverter(@Nullable MessageConverter messageConverter) {
 		this.messageConverter = messageConverter;
 	}
 
@@ -53,7 +55,7 @@ public class RabbitStreamTemplateConfigurer {
 	 * stream message converter should be used.
 	 * @param streamMessageConverter the {@link StreamMessageConverter}
 	 */
-	public void setStreamMessageConverter(StreamMessageConverter streamMessageConverter) {
+	public void setStreamMessageConverter(@Nullable StreamMessageConverter streamMessageConverter) {
 		this.streamMessageConverter = streamMessageConverter;
 	}
 
@@ -61,7 +63,7 @@ public class RabbitStreamTemplateConfigurer {
 	 * Set the {@link ProducerCustomizer} instances to use.
 	 * @param producerCustomizer the producer customizer
 	 */
-	public void setProducerCustomizer(ProducerCustomizer producerCustomizer) {
+	public void setProducerCustomizer(@Nullable ProducerCustomizer producerCustomizer) {
 		this.producerCustomizer = producerCustomizer;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitTemplateConfigurer.java

@@ -19,6 +19,8 @@ package org.springframework.boot.amqp.autoconfigure;
 import java.time.Duration;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.rabbit.connection.ConnectionFactory;
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
 import org.springframework.amqp.support.converter.AllowedListDeserializingMessageConverter;
@@ -42,9 +44,9 @@ import org.springframework.util.CollectionUtils;
  */
 public class RabbitTemplateConfigurer {
 
-	private MessageConverter messageConverter;
+	private @Nullable MessageConverter messageConverter;
 
-	private List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers;
+	private @Nullable List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers;
 
 	private final RabbitProperties rabbitProperties;
 
@@ -62,7 +64,7 @@ public class RabbitTemplateConfigurer {
 	 * converter should be used.
 	 * @param messageConverter the {@link MessageConverter}
 	 */
-	public void setMessageConverter(MessageConverter messageConverter) {
+	public void setMessageConverter(@Nullable MessageConverter messageConverter) {
 		this.messageConverter = messageConverter;
 	}
 
@@ -70,7 +72,7 @@ public class RabbitTemplateConfigurer {
 	 * Set the {@link RabbitRetryTemplateCustomizer} instances to use.
 	 * @param retryTemplateCustomizers the retry template customizers
 	 */
-	public void setRetryTemplateCustomizers(List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers) {
+	public void setRetryTemplateCustomizers(@Nullable List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers) {
 		this.retryTemplateCustomizers = retryTemplateCustomizers;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RetryTemplateFactory.java

@@ -19,6 +19,8 @@ package org.springframework.boot.amqp.autoconfigure;
 import java.time.Duration;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.retry.backoff.ExponentialBackOffPolicy;
 import org.springframework.retry.policy.SimpleRetryPolicy;
@@ -32,9 +34,9 @@ import org.springframework.retry.support.RetryTemplate;
  */
 class RetryTemplateFactory {
 
-	private final List<RabbitRetryTemplateCustomizer> customizers;
+	private final @Nullable List<RabbitRetryTemplateCustomizer> customizers;
 
-	RetryTemplateFactory(List<RabbitRetryTemplateCustomizer> customizers) {
+	RetryTemplateFactory(@Nullable List<RabbitRetryTemplateCustomizer> customizers) {
 		this.customizers = customizers;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/SslBundleRabbitConnectionFactoryBean.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.amqp.autoconfigure;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.rabbit.connection.RabbitConnectionFactoryBean;
 import org.springframework.boot.ssl.SslBundle;
 
@@ -27,7 +29,7 @@ import org.springframework.boot.ssl.SslBundle;
  */
 class SslBundleRabbitConnectionFactoryBean extends RabbitConnectionFactoryBean {
 
-	private SslBundle sslBundle;
+	private @Nullable SslBundle sslBundle;
 
 	private boolean enableHostnameVerification;
 
@@ -44,7 +46,7 @@ class SslBundleRabbitConnectionFactoryBean extends RabbitConnectionFactoryBean {
 		}
 	}
 
-	void setSslBundle(SslBundle sslBundle) {
+	void setSslBundle(@Nullable SslBundle sslBundle) {
 		this.sslBundle = sslBundle;
 	}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/health/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for RabbitMQ health.
  */
+@NullMarked
 package org.springframework.boot.amqp.autoconfigure.health;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/metrics/RabbitConnectionFactoryMetricsPostProcessor.java

@@ -20,6 +20,7 @@ import com.rabbitmq.client.ConnectionFactory;
 import com.rabbitmq.client.MetricsCollector;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Tags;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.amqp.rabbit.connection.AbstractConnectionFactory;
 import org.springframework.beans.factory.config.BeanPostProcessor;
@@ -41,7 +42,7 @@ class RabbitConnectionFactoryMetricsPostProcessor implements BeanPostProcessor,
 
 	private final ApplicationContext context;
 
-	private volatile MeterRegistry meterRegistry;
+	private volatile @Nullable MeterRegistry meterRegistry;
 
 	RabbitConnectionFactoryMetricsPostProcessor(ApplicationContext context) {
 		this.context = context;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/metrics/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for RabbitMQ metrics.
  */
+@NullMarked
 package org.springframework.boot.amqp.autoconfigure.metrics;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for RabbitMQ.
  */
+@NullMarked
 package org.springframework.boot.amqp.autoconfigure;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/docker/compose/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Support for Docker Compose RabbitMQ service connections.
  */
+@NullMarked
 package org.springframework.boot.amqp.docker.compose;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/health/RabbitHealthIndicator.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.amqp.health;
 
+import org.jspecify.annotations.Nullable;
+
 import org.springframework.amqp.rabbit.core.RabbitTemplate;
 import org.springframework.boot.health.contributor.AbstractHealthIndicator;
 import org.springframework.boot.health.contributor.Health;
@@ -44,9 +46,12 @@ public class RabbitHealthIndicator extends AbstractHealthIndicator {
 		builder.up().withDetail("version", getVersion());
 	}
 
-	private String getVersion() {
-		return this.rabbitTemplate
-			.execute((channel) -> channel.getConnection().getServerProperties().get("version").toString());
+	private @Nullable String getVersion() {
+		return this.rabbitTemplate.execute((channel) -> {
+			Object version = channel.getConnection().getServerProperties().get("version");
+			Assert.state(version != null, "'version' must not be null");
+			return version.toString();
+		});
 	}
 
 }

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/health/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Health integration for AMQP and RabbitMQ.
  */
+@NullMarked
 package org.springframework.boot.amqp.health;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/metrics/RabbitMetrics.java

@@ -23,6 +23,7 @@ import com.rabbitmq.client.impl.MicrometerMetricsCollector;
 import io.micrometer.core.instrument.MeterRegistry;
 import io.micrometer.core.instrument.Tag;
 import io.micrometer.core.instrument.binder.MeterBinder;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.util.Assert;
 
@@ -44,7 +45,7 @@ public class RabbitMetrics implements MeterBinder {
 	 * @param connectionFactory the {@link ConnectionFactory} to instrument
 	 * @param tags tags to apply to all recorded metrics
 	 */
-	public RabbitMetrics(ConnectionFactory connectionFactory, Iterable<Tag> tags) {
+	public RabbitMetrics(ConnectionFactory connectionFactory, @Nullable Iterable<Tag> tags) {
 		Assert.notNull(connectionFactory, "'connectionFactory' must not be null");
 		this.connectionFactory = connectionFactory;
 		this.tags = (tags != null) ? tags : Collections.emptyList();

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/metrics/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Metrics for AMQP and RabbitMQ.
  */
+@NullMarked
 package org.springframework.boot.amqp.metrics;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitContainerConnectionDetailsFactory.java

@@ -19,6 +19,7 @@ package org.springframework.boot.amqp.testcontainers;
 import java.net.URI;
 import java.util.List;
 
+import org.jspecify.annotations.Nullable;
 import org.testcontainers.containers.RabbitMQContainer;
 
 import org.springframework.boot.amqp.autoconfigure.RabbitConnectionDetails;
@@ -72,7 +73,7 @@ class RabbitContainerConnectionDetailsFactory
 		}
 
 		@Override
-		public SslBundle getSslBundle() {
+		public @Nullable SslBundle getSslBundle() {
 			return super.getSslBundle();
 		}
 

module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Support for testcontainers RabbitMQ service connections.
  */
+@NullMarked
 package org.springframework.boot.amqp.testcontainers;
+
+import org.jspecify.annotations.NullMarked;