Package org.axonframework.messaging.eventhandling.configuration

Class EventProcessingConfigurer

java.lang.Object

org.axonframework.messaging.eventhandling.configuration.EventProcessingConfigurer

public class EventProcessingConfigurer
extends Object

A configuration module for event processing that provides a unified way to configure and manage both EventProcessor types:

• PooledStreamingEventProcessor
• SubscribingEventProcessor

The EventProcessingConfigurer acts as a composite module that delegates event EventProcessorConfiguration to specialized sub-modules: PooledStreamingEventProcessorsConfigurer for PooledStreamingEventProcessor instances and SubscribingEventProcessorsConfigurer for SubscribingEventProcessor instances.

The main purpose is to provide shared configuration capabilities for all event processor types, allowing you to set default configurations like UnitOfWorkFactory that apply to all processors while still enabling type-specific customizations.

The module automatically configures default transaction management by registering a TransactionalUnitOfWorkFactory when a TransactionManager is available in the configuration.

This module is automatically created and registered by the MessagingConfigurer when the application starts, so you typically don't need to instantiate it manually. Instead, access it through MessagingConfigurer.eventProcessing(java.util.function.Consumer).

Example usage:

 MessagingConfigurer.create()
     .eventProcessing(eventProcessing -> eventProcessing
         .defaults(config -> config.unitOfWorkFactory(new SimpleUnitOfWorkFactory()))
         .pooledStreaming(pooledStreaming ->
             pooledStreaming.processor("calendar-processor", components -> components.declarative(cfg -> weekStartedEventHandler))
                        .processor("astrologers-week-symbol-processor", components -> components.declarative(cfg -> weekSymbolProclaimedEventHandler)))
         .subscribing(subscribing ->
             subscribing.processor("creatures-dwelling-readmodel", components -> components.autodetected(cfg -> dwellingBuiltEventHandler)));
 

Since:

5.0.0

Author:

Mateusz Nowak

Constructor Summary

Constructors

Constructor	Description
EventProcessingConfigurer(MessagingConfigurer parent)	Constructs a new event processing module with the given name.

Method Summary

Modifier and Type	Method	Description
void	build()	Builds the configurer, registering the necessary modules and customizations.
EventProcessingConfigurer	componentRegistry(Consumer<ComponentRegistry> componentRegistrar)	Executes the given componentRegistrar on the component registry associated with the MessagingConfigurer, which is the parent of this configurer.
EventProcessingConfigurer	defaults(BiFunction<Configuration,EventProcessorConfiguration,EventProcessorConfiguration> configureDefaults)	Configures default settings that will be applied to all event processors managed by this module.
EventProcessingConfigurer	defaults(UnaryOperator<EventProcessorConfiguration> configureDefaults)	Configures default settings that will be applied to all event processors managed by this module.
EventProcessingConfigurer	pooledStreaming(UnaryOperator<PooledStreamingEventProcessorsConfigurer> processorsModuleTask)	Provides access to configure PooledStreamingEventProcessor instances through the PooledStreamingEventProcessorsConfigurer.
EventProcessingConfigurer	subscribing(UnaryOperator<SubscribingEventProcessorsConfigurer> processorsModuleTask)	Provides access to configure SubscribingEventProcessor instances through the SubscribingEventProcessorsConfigurer.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

EventProcessingConfigurer

@Internal
public EventProcessingConfigurer(@Nonnull
 MessagingConfigurer parent)

Constructs a new event processing module with the given name.

This constructor is marked as Internal because the module is automatically created and managed by the MessagingConfigurer. Typically, users should not instantiate this class directly but instead access it through MessagingConfigurer.eventProcessing(java.util.function.Consumer).

Parameters:

parent - The MessagingConfigurer to enhance with configuration of event processing components.

Method Details

build

public void build()

Builds the configurer, registering the necessary modules and customizations.

This method is typically called by the MessagingConfigurer during application startup to finalize the configuration of event processors.

defaults

public EventProcessingConfigurer defaults(@Nonnull
 BiFunction<Configuration,EventProcessorConfiguration,EventProcessorConfiguration> configureDefaults)

Configures default settings that will be applied to all event processors managed by this module.

This method allows you to specify configurations that should be shared across both pooled streaming and subscribing event processors. The provided function receives both the Axon Configuration and the EventProcessorConfiguration, allowing access to application-wide components when setting defaults.

Common use cases include setting default UnitOfWorkFactory, error handlers, or processing policies that should apply to all processors unless explicitly overridden.

Parameters:

configureDefaults - A function that receives the Axon configuration and EventProcessorConfiguration, returning a modified EventProcessorConfiguration with the desired defaults applied.

Returns:

This module instance for method chaining.

defaults

public EventProcessingConfigurer defaults(@Nonnull
 UnaryOperator<EventProcessorConfiguration> configureDefaults)

Configures default settings that will be applied to all event processors managed by this module.

This is a simplified version of defaults(BiFunction) that provides only the EventProcessorConfiguration for modification, without access to the Axon Configuration. Use this when your default configurations don't require components from the application Configuration.

Parameters:

configureDefaults - A function that modifies the EventProcessorConfiguration with desired defaults.

Returns:

This module instance for method chaining.

pooledStreaming

public EventProcessingConfigurer pooledStreaming(@Nonnull
 UnaryOperator<PooledStreamingEventProcessorsConfigurer> processorsModuleTask)

Provides access to configure PooledStreamingEventProcessor instances through the PooledStreamingEventProcessorsConfigurer.

Use this method to define specific pooled streaming event processors, set their configurations, and register event handling components. The provided function receives the module for PooledStreamingEventProcessors and can register individual processors or configure module-wide settings.

Parameters:

processorsModuleTask - A function that configures the PooledStreamingEventProcessorsConfigurer.

Returns:

This module instance for method chaining.

subscribing

public EventProcessingConfigurer subscribing(@Nonnull
 UnaryOperator<SubscribingEventProcessorsConfigurer> processorsModuleTask)

Provides access to configure SubscribingEventProcessor instances through the SubscribingEventProcessorsConfigurer.

Use this method to define specific subscribing event processors, set their configurations, and register event handling components. The provided function receives the module for SubscribingEventProcessors and can register individual processors or configure module-wide settings.

Parameters:

processorsModuleTask - A function that configures the SubscribingEventProcessorsConfigurer.

Returns:

This module instance for method chaining.

componentRegistry

public EventProcessingConfigurer componentRegistry(@Nonnull
 Consumer<ComponentRegistry> componentRegistrar)

Executes the given componentRegistrar on the component registry associated with the MessagingConfigurer, which is the parent of this configurer.

Parameters:

componentRegistrar - The actions to take on the component registry.

Returns:

This EventProcessingConfigurer for a fluent API.