org.axonframework.eventhandling

Interface EventMessageHandler

All Superinterfaces:

MessageHandler<EventMessage<?>>

All Known Subinterfaces:

Saga<T>

All Known Implementing Classes:

AnnotatedSaga, AnnotationEventHandlerAdapter, EventValidator

public interface EventMessageHandler
extends MessageHandler<EventMessage<?>>

Interface to be implemented by classes that can handle events.

Since:

0.1

Author:

Allard Buijze

See Also:

EventBus, DomainEventMessage, EventHandler

Method Summary

Modifier and Type	Method and Description
Object	handle(EventMessage<?> event) Process the given event.
default void	prepareReset() Performs any activities that are required to reset the state managed by handlers assigned to this handler.
default <R> void	prepareReset(R resetContext) Performs any activities that are required to reset the state managed by handlers assigned to this handler.
default boolean	supportsReset() Indicates whether the handlers managed by this invoker support a reset.

Methods inherited from interface org.axonframework.messaging.MessageHandler

canHandle, canHandleType, getTargetType

Method Detail

handle

Object handle(EventMessage<?> event)
       throws Exception

Process the given event. The implementation may decide to process or skip the given event. It is highly unrecommended to throw any exception during the event handling process.

Specified by:

handle in interface MessageHandler<EventMessage<?>>

Parameters:

event - the event to handle

Returns:

the result of the event handler invocation. Is generally ignored

Throws:

Exception - when an exception is raised during event handling

prepareReset

default void prepareReset()

Performs any activities that are required to reset the state managed by handlers assigned to this handler.

prepareReset

default <R> void prepareReset(R resetContext)

Performs any activities that are required to reset the state managed by handlers assigned to this handler.

Type Parameters:

R - the type of the provided resetContext

Parameters:

resetContext - a R used to support the reset operation

supportsReset

default boolean supportsReset()

Indicates whether the handlers managed by this invoker support a reset.

Returns:

true if a reset is supported, otherwise false