Add nullability annotations to module/spring-boot-amqp

See gh-46587

Author: mhalbritter

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 @@
 
 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 @@ protected AbstractConnectionFactoryConfigurer(RabbitProperties properties,
 		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 @@
 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 @@
  */
 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}.
@@ -63,31 +65,31 @@ protected AbstractRabbitListenerContainerFactoryConfigurer(RabbitProperties rabb
 	 * converter should be used.
 	 * @param messageConverter the {@link MessageConverter}
 	 */
-	protected void setMessageConverter(MessageConverter messageConverter) {
+	protected void setMessageConverter(@Nullable MessageConverter messageConverter) {
 		this.messageConverter = messageConverter;
 	}
 
 	/**
 	 * 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;
 	}
 
 	/**
 	 * 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;
 	}
 
 	/**
 	 * 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 @@
 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 @@ public String getUsername() {
 	}
 
 	@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 @@ public List<Address> getAddresses() {
 	}
 
 	@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 @@
 
 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;
@@ -36,23 +38,23 @@ 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;
 	}
 
 	/**
 	 * 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;
 	}
 
 	/**
 	 * 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 @@ default Address getFirstAddress() {
 	 * 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 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 RabbitConnectionFactoryBeanConfigurer(ResourceLoader resourceLoader, Rabb
 	 * @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 RabbitConnectionFactoryBeanConfigurer(ResourceLoader resourceLoader, Rabb
 		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;
 	}