Package org.axonframework.messaging.commandhandling

Interface CommandHandlingExceptionHandler

All Superinterfaces:

MessageHandlingExceptionHandler<CommandMessage>

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface CommandHandlingExceptionHandler
extends MessageHandlingExceptionHandler<CommandMessage>

Handles exceptions thrown by a CommandHandler within a CommandHandlingComponent.

Return MessageStream.empty() to suppress the exception. Return MessageStream.failed(Throwable) (with the same or a different exception) to let the error propagate to the caller. Return MessageStream.just(org.axonframework.messaging.core.Message) with a CommandResultMessage to substitute a result in place of the error.

The return type is MessageStream.Single because command handling always produces at most one result, matching the contract of CommandHandler.handle(CommandMessage, ProcessingContext).

Register via CommandHandlingModule.CommandHandlerPhase.withExceptionHandler(org.axonframework.common.configuration.ComponentBuilder).

Since:

5.2.0

Author:

Allard Buijze

Method Summary

Modifier and Type	Method	Description
MessageStream.Single<CommandResultMessage>	handle(CommandMessage command, ProcessingContext context, Throwable error)	Called when a command handler throws an exception.

Method Details

handle

MessageStream.Single<CommandResultMessage> handle(CommandMessage command,
 ProcessingContext context,
 Throwable error)

Called when a command handler throws an exception.

Specified by:

handle in interface MessageHandlingExceptionHandler<CommandMessage>

Parameters:

command - the command being handled when the exception occurred

context - the active processing context

error - the exception thrown by the command handler

Returns:

MessageStream.empty() to suppress the error, MessageStream.failed(Throwable) to propagate it, or MessageStream.just(org.axonframework.messaging.core.Message) to substitute a result