org.axonframework.commandhandling

Class LoggingDuplicateCommandHandlerResolver

java.lang.Object

org.axonframework.commandhandling.LoggingDuplicateCommandHandlerResolver

All Implemented Interfaces:

DuplicateCommandHandlerResolver

public class LoggingDuplicateCommandHandlerResolver
extends Object
implements DuplicateCommandHandlerResolver

Implementation of the DuplicateCommandHandlerResolver that allows registrations to be overridden by new handlers, but logs this (on WARN level) to a given logger.

Since:

4.2

Author:

Allard Buijze

Method Summary

Modifier and Type	Method and Description
static LoggingDuplicateCommandHandlerResolver	instance() Returns an instance that logs duplicate registrations.
MessageHandler<? super CommandMessage<?>>	resolve(String commandName, MessageHandler<? super CommandMessage<?>> registeredHandler, MessageHandler<? super CommandMessage<?>> candidateHandler) Chooses what to do when a duplicate handler is registered, returning the handler that should be selected for command handling, or otherwise throwing an exception to reject registration altogether.

Methods inherited from class java.lang.Object

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

Method Detail

instance

public static LoggingDuplicateCommandHandlerResolver instance()

Returns an instance that logs duplicate registrations.

Returns:

an instance that logs duplicate registrations

resolve

public MessageHandler<? super CommandMessage<?>> resolve(@Nonnull
                                                         String commandName,
                                                         @Nonnull
                                                         MessageHandler<? super CommandMessage<?>> registeredHandler,
                                                         @Nonnull
                                                         MessageHandler<? super CommandMessage<?>> candidateHandler)

Description copied from interface: DuplicateCommandHandlerResolver

Chooses what to do when a duplicate handler is registered, returning the handler that should be selected for command handling, or otherwise throwing an exception to reject registration altogether.

Specified by:

resolve in interface DuplicateCommandHandlerResolver

Parameters:

commandName - The name of the Command for which the duplicate was detected

registeredHandler - the MessageHandler previously registered with the Command Bus

candidateHandler - the MessageHandler that is newly registered and conflicts with the existing registration

Returns:

the resolved MessageHandler. Could be the registeredHandler, the candidateHandler or another handler entirely