org.axonframework.queryhandling.registration

Class LoggingDuplicateQueryHandlerResolver

java.lang.Object

org.axonframework.queryhandling.registration.LoggingDuplicateQueryHandlerResolver

All Implemented Interfaces:

DuplicateQueryHandlerResolver

public class LoggingDuplicateQueryHandlerResolver
extends Object
implements DuplicateQueryHandlerResolver

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

Since:

4.6.0

Author:

Mitchell Herrijgers

Method Summary

Modifier and Type	Method and Description
static LoggingDuplicateQueryHandlerResolver	instance() Returns an instance that logs duplicate registrations.
List<QuerySubscription<?>>	resolve(String queryName, Type responseType, List<QuerySubscription<?>> registeredHandlers, QuerySubscription<?> candidateHandler) Chooses what to do when a duplicate handler is registered, returning the handlers that should be selected for query 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 LoggingDuplicateQueryHandlerResolver instance()

Returns an instance that logs duplicate registrations.

Returns:

an instance that logs duplicate registrations

resolve

public List<QuerySubscription<?>> resolve(String queryName,
                                          Type responseType,
                                          List<QuerySubscription<?>> registeredHandlers,
                                          QuerySubscription<?> candidateHandler)

Description copied from interface: DuplicateQueryHandlerResolver

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

Specified by:

resolve in interface DuplicateQueryHandlerResolver

Parameters:

queryName - The name of the query for which the duplicate was detected

registeredHandlers - the MessageHandler instances already registered with the Query Bus

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

Returns:

the resolved MessageHandler instances. It is up to the implementation to discard implementations already in the list