Messaging Auto-Configuration

Relevant source files

• core/spring-boot-testcontainers/src/main/java/org/springframework/boot/testcontainers/service/connection/ContainerConnectionSource.java
• core/spring-boot/src/main/java/org/springframework/boot/retry/RetryPolicySettings.java
• core/spring-boot/src/main/java/org/springframework/boot/retry/package-info.java
• core/spring-boot/src/test/java/org/springframework/boot/retry/RetryPolicySettingsTests.java
• documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/amqp.adoc
• documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/kafka.adoc
• documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/rsocket.adoc
• module/spring-boot-amqp/build.gradle
• module/spring-boot-amqp/src/dockerTest/java/org/springframework/boot/amqp/testcontainers/RabbitContainerConnectionDetailsFactoryIntegrationTests.java
• module/spring-boot-amqp/src/dockerTest/java/org/springframework/boot/amqp/testcontainers/RabbitStreamContainerConnectionDetailsFactoryIntegrationTests.java
• module/spring-boot-amqp/src/dockerTest/java/org/springframework/boot/amqp/testcontainers/SeparateContainersRabbitAndRabbitStreamContainerConnectionDetailsFactoryIntegrationTests.java
• module/spring-boot-amqp/src/dockerTest/java/org/springframework/boot/amqp/testcontainers/SingleContainerRabbitAndRabbitStreamContainerConnectionDetailsFactoryIntegrationTests.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/AbstractRabbitListenerContainerFactoryConfigurer.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAnnotationDrivenConfiguration.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfiguration.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitListenerRetrySettingsCustomizer.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitProperties.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitRetryTemplateSettings.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfiguration.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConnectionDetails.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamTemplateConfigurer.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitTemplateConfigurer.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/docker/compose/RabbitStreamDockerComposeConnectionDetailsFactory.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitContainerConnectionDetailsFactory.java
• module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitStreamContainerConnectionDetailsFactory.java
• module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfigurationTests.java
• module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/autoconfigure/RabbitPropertiesTests.java
• module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfigurationTests.java
• module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/health/RabbitHealthIndicatorTests.java
• module/spring-boot-jackson/src/main/java/org/springframework/boot/jackson/autoconfigure/CborMapperBuilderCustomizer.java
• module/spring-boot-jackson/src/main/java/org/springframework/boot/jackson/autoconfigure/JacksonCborProperties.java
• module/spring-boot-jdbc/src/main/java/org/springframework/boot/jdbc/autoconfigure/EmbeddedDataSourceConfiguration.java
• module/spring-boot-jetty/src/main/java/org/springframework/boot/jetty/autoconfigure/JettyWebServerConfiguration.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/ConcurrentKafkaListenerContainerFactoryConfigurer.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAnnotationDrivenConfiguration.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfiguration.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaConnectionDetails.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaProperties.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaStreamsAnnotationDrivenConfiguration.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/PropertiesKafkaConnectionDetails.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/SslBundleSslEngineFactory.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/metrics/KafkaMetricsAutoConfiguration.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/metrics/package-info.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/package-info.java
• module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/testcontainers/ApacheKafkaContainerConnectionDetailsFactory.java
• module/spring-boot-kafka/src/main/resources/META-INF/additional-spring-configuration-metadata.json
• module/spring-boot-kafka/src/test/java/org/springframework/boot/kafka/autoconfigure/ConcurrentKafkaListenerContainerFactoryConfigurerTests.java
• module/spring-boot-kafka/src/test/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfigurationTests.java
• module/spring-boot-rsocket/build.gradle
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfiguration.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketProperties.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketServerAutoConfiguration.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketStrategiesAutoConfiguration.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/package-info.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/context/RSocketServerBootstrap.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/context/package-info.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/messaging/package-info.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/netty/NettyRSocketServer.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/netty/NettyRSocketServerFactory.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/netty/package-info.java
• module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/server/ConfigurableRSocketServerFactory.java
• module/spring-boot-rsocket/src/main/resources/META-INF/additional-spring-configuration-metadata.json
• module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfigurationTests.java
• module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/autoconfigure/RSocketStrategiesAutoConfigurationTests.java
• module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/autoconfigure/RSocketWebSocketNettyRouteProviderTests.java
• module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/netty/NettyRSocketServerFactoryTests.java
• module/spring-boot-web-server/src/main/java/org/springframework/boot/web/server/autoconfigure/reactive/ReactiveWebServerConfiguration.java
• module/spring-boot-websocket/build.gradle
• module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java
• module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/package-info.java
• module/spring-boot-websocket/src/main/resources/META-INF/additional-spring-configuration-metadata.json
• module/spring-boot-websocket/src/test/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfigurationTests.java

The messaging integration in Spring Boot provides comprehensive auto-configuration for various message brokers and protocols. This system abstracts connection details, simplifies the creation of templates and listener containers, and provides seamless integration with testing infrastructure like Testcontainers and Docker Compose.

Connection Details Abstraction

Spring Boot uses the ConnectionDetails interface hierarchy to decouple the application from the specific source of connection parameters (e.g., static properties, Docker Compose, or Testcontainers).

Broker	Connection Details Interface	Implementation
RabbitMQ	RabbitConnectionDetails	PropertiesRabbitConnectionDetails
Rabbit Stream	RabbitStreamConnectionDetails	PropertiesRabbitStreamConnectionDetails
Kafka	KafkaConnectionDetails	PropertiesKafkaConnectionDetails

For example, RabbitStreamConnectionDetails provides the host, port, and credentials required for the RabbitMQ Stream plugin module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConnectionDetails.java23-53

Integration with Docker and Testcontainers

Spring Boot provides automatic discovery of connection details when using Testcontainers or Docker Compose.

• Testcontainers: RabbitContainerConnectionDetailsFactory and RabbitStreamContainerConnectionDetailsFactory create connection details from running containers during tests module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitContainerConnectionDetailsFactory.java33-35 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitStreamContainerConnectionDetailsFactory.java33-35
• Docker Compose: RabbitStreamDockerComposeConnectionDetailsFactory extracts connection information from services defined in docker-compose.yml module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/docker/compose/RabbitStreamDockerComposeConnectionDetailsFactory.java32-34

Sources: module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConnectionDetails.java23-53 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitContainerConnectionDetailsFactory.java33-35 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/testcontainers/RabbitStreamContainerConnectionDetailsFactory.java33-35 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/docker/compose/RabbitStreamDockerComposeConnectionDetailsFactory.java32-34

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Apache Kafka

Auto-configuration for Apache Kafka is managed by KafkaAutoConfiguration. It sets up the core infrastructure including KafkaTemplate, ConsumerFactory, and ProducerFactory.

Data Flow and Core Components

The following diagram illustrates the relationship between properties, connection details, and the resulting Kafka beans.

Kafka Auto-Configuration Logic

Key Functions

• kafkaTemplate: Configures a KafkaTemplate for sending messages. It automatically associates a RecordMessageConverter and KafkaTemplateObservationConvention if present module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfiguration.java105-122
• kafkaConsumerFactory: Creates a DefaultKafkaConsumerFactory using properties built from KafkaProperties and overrides from KafkaConnectionDetails module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfiguration.java131-139
• Kafka Streams: Enabled via @EnableKafkaStreams. Spring Boot auto-configures KafkaStreamsConfiguration and StreamsBuilderFactoryBean documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/kafka.adoc61-65

Sources: module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfiguration.java90-148 documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/kafka.adoc4-81 module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaProperties.java64-229

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RabbitMQ / AMQP

Spring Boot supports both standard AMQP and the RabbitMQ Stream plugin.

RabbitMQ Auto-Configuration

RabbitAutoConfiguration initializes the CachingConnectionFactory, RabbitTemplate, and AmqpAdmin module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfiguration.java133-145

• Retry Support: Can be enabled via spring.rabbitmq.template.retry.enabled documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/amqp.adoc64-74
• Observation: Automatically configures RabbitTemplateObservationConvention if a bean is available module/spring-boot-amqp/src/test/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfigurationTests.java74-75

RabbitMQ Stream

Configured via RabbitStreamConfiguration, this module provides support for the high-performance Stream plugin.

• rabbitStreamEnvironment: Configures the com.rabbitmq.stream.Environment required for stream operations module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfiguration.java92-101
• rabbitStreamTemplate: Auto-configured when spring.rabbitmq.stream.name is set, allowing for stream-specific message production module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfiguration.java119-128

Sources: module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfiguration.java133-145 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitStreamConfiguration.java92-128 documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/amqp.adoc64-74

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RSocket

RSocket support is split between strategy configuration and messaging infrastructure.

RSocket Infrastructure

• RSocketStrategiesAutoConfiguration: Configures encoders and decoders (e.g., JSON, CBOR) into an RSocketStrategies bean module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketStrategiesAutoConfiguration.java46-51
• RSocketMessagingAutoConfiguration: Configures the RSocketMessageHandler which handles @MessageMapping annotations module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfiguration.java49-56

RSocket Component Interaction

Sources: module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketStrategiesAutoConfiguration.java46-51 module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfiguration.java49-56 module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfigurationTests.java59-105

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WebSocket Messaging

WebSocket messaging auto-configuration (WebSocketMessagingAutoConfiguration) is focused on STOMP-based messaging over WebSockets within a Servlet environment module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java61-66

• Message Converters: Automatically configures JacksonJsonMessageConverter if JsonMapper is on the classpath module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java85-103
• Task Executors: Automatically associates the applicationTaskExecutor with the message broker if available module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java159-165
• Lazy Initialization: Specifically excludes stompWebSocketHandlerMapping from lazy initialization via LazyInitializationExcludeFilter to ensure WebSocket endpoints are registered correctly on startup module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java68-71

Sources: module/spring-boot-websocket/src/main/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfiguration.java61-172 module/spring-boot-websocket/src/test/java/org/springframework/boot/websocket/autoconfigure/servlet/WebSocketMessagingAutoConfigurationTests.java118-149

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JMS and Other Brokers

Spring Boot continues to support traditional messaging systems:

• ActiveMQ / Artemis: Auto-configures ConnectionFactory and JmsTemplate.
• Pulsar: (See section 4.5 for detailed Pulsar integration) providing PulsarTemplate and listener container factories.
• JMS: Standard JMS support via JmsAutoConfiguration.

All these modules follow the same pattern:

1. Map ConfigurationProperties to a broker-specific ConnectionFactory.
2. Provide a Template for sending (e.g., JmsTemplate).
3. Configure a ListenerContainerFactory for receiving via @JmsListener or similar annotations.

Sources: module/spring-boot-kafka/src/main/java/org/springframework/boot/kafka/autoconfigure/KafkaAutoConfiguration.java90-148 module/spring-boot-amqp/src/main/java/org/springframework/boot/amqp/autoconfigure/RabbitAutoConfiguration.java133-145