Package io.axoniq.framework.messaging.eventhandling.deadletter

Class DeadLetterQueueConfigurationEnhancer

java.lang.Object

io.axoniq.framework.messaging.eventhandling.deadletter.DeadLetterQueueConfigurationEnhancer

All Implemented Interfaces:

ConfigurationEnhancer

public class DeadLetterQueueConfigurationEnhancer
extends Object
implements ConfigurationEnhancer

A ConfigurationEnhancer that adds Dead Letter Queue (DLQ) support to EventHandlingComponents within a pooled streaming event processor module.

This enhancer registers:

• A ComponentFactory for SequencedDeadLetterQueue — creates queue instances on demand, optionally wrapped with CachingSequencedDeadLetterQueue
• A type-level decorator for EventHandlingComponent — wraps components with DeadLetteringEventHandlingComponent when DLQ is enabled
• A ComponentFactory for SequencedDeadLetterProcessor — makes DLQ-decorated components discoverable as dead letter processors

This enhancer operates only within module scopes that contain a PooledStreamingEventProcessorConfiguration. In all other contexts (e.g., non-pooled processors), the decorator returns the delegate unchanged.

Since:

5.1.0

Author:

Mateusz Nowak

See Also:

• DeadLetterQueueConfiguration
• DeadLetteringEventHandlingComponent
• CachingSequencedDeadLetterQueue

Field Summary

Fields

Modifier and Type	Field	Description
static final int	ENHANCER_ORDER	The order of this enhancer.

Constructor Summary

Constructors

Constructor	Description
DeadLetterQueueConfigurationEnhancer()

Method Summary

Modifier and Type	Method	Description
void	enhance(ComponentRegistry registry)	Enhances the given registry with, for example, additional components and decorators.
int	order()	Returns the relative order this enhancer should be invoked in, compared to other instances.

Methods inherited from class java.lang.Object

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

Field Details

ENHANCER_ORDER

public static final int ENHANCER_ORDER

The order of this enhancer. Runs late so that the DeadLetteringEventHandlingComponent wraps all other decorators, making it discoverable as a SequencedDeadLetterProcessor.

Set to Integer.MAX_VALUE - 100 — after all normal enhancers but before MessagingConfigurationDefaults (Integer.MAX_VALUE).

See Also:

• Constant Field Values

Constructor Details

DeadLetterQueueConfigurationEnhancer

public DeadLetterQueueConfigurationEnhancer()

Method Details

order

public int order()

Description copied from interface: ConfigurationEnhancer

Returns the relative order this enhancer should be invoked in, compared to other instances.

Use lower (negative) values for enhancers providing sensible defaults, and higher values for enhancers that should be able to override values potentially previously set. Defaults to 0 when not set.

Specified by:

order in interface ConfigurationEnhancer

Returns:

The order in which this enhancer should be invoked.

enhance

public void enhance(ComponentRegistry registry)

Description copied from interface: ConfigurationEnhancer

Enhances the given registry with, for example, additional components and decorators.

Specified by:

enhance in interface ConfigurationEnhancer

Parameters:

registry - The registry instance to enhance.