org.axonframework.eventhandling

Class SimpleEventHandlerInvoker

java.lang.Object

org.axonframework.eventhandling.SimpleEventHandlerInvoker

All Implemented Interfaces:

EventHandlerInvoker

Direct Known Subclasses:

DeadLetteringEventHandlerInvoker

public class SimpleEventHandlerInvoker
extends Object
implements EventHandlerInvoker

Implementation of an EventHandlerInvoker that forwards events to a list of registered EventMessageHandler.

Since:

3.0

Author:

Rene de Waele

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SimpleEventHandlerInvoker.Builder<B extends SimpleEventHandlerInvoker.Builder<?>> Builder class to instantiate a SimpleEventHandlerInvoker.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleEventHandlerInvoker(SimpleEventHandlerInvoker.Builder<?> builder) Instantiate a SimpleEventHandlerInvoker based on the fields contained in the SimpleEventHandlerInvoker.Builder.

Method Summary

Modifier and Type	Method and Description
static <B extends SimpleEventHandlerInvoker.Builder<?>> SimpleEventHandlerInvoker.Builder<B>	builder() Instantiate a Builder to be able to create a SimpleEventHandlerInvoker.
boolean	canHandle(EventMessage<?> eventMessage, Segment segment) Check whether or not this invoker has handlers that can handle the given eventMessage for a given segment.
boolean	canHandleType(Class<?> payloadType) Check whether or not this invoker has handlers that can handle the given payloadType.
List<EventMessageHandler>	eventHandlers() Gets the list of EventMessageHandler delegates in this invoker.
ListenerInvocationErrorHandler	getListenerInvocationErrorHandler() Return the ListenerInvocationErrorHandler as configured for this EventHandlerInvoker.
SequencingPolicy<? super EventMessage<?>>	getSequencingPolicy() Return the SequencingPolicy as configured for this EventHandlerInvoker.
void	handle(EventMessage<?> message, Segment segment) Handle the given message for the given segment.
protected void	invokeHandlers(EventMessage<?> message)
void	performReset() Performs any activities that are required to reset the state managed by handlers assigned to this invoker.
<R> void	performReset(R resetContext) Performs any activities that are required to reset the state managed by handlers assigned to this invoker.
protected Object	sequenceIdentifier(EventMessage<?> event)
protected boolean	sequencingPolicyMatchesSegment(EventMessage<?> message, Segment segment)
boolean	supportsReset() Indicates whether the handlers managed by this invoker support a reset.

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleEventHandlerInvoker

protected SimpleEventHandlerInvoker(SimpleEventHandlerInvoker.Builder<?> builder)

Instantiate a SimpleEventHandlerInvoker based on the fields contained in the SimpleEventHandlerInvoker.Builder.

Will assert that at least one EventMessageHandler is provided, and will throw an AxonConfigurationException if this is not the case.

Parameters:

builder - the SimpleEventHandlerInvoker.Builder used to instantiate a SimpleEventHandlerInvoker instance

Method Detail

builder

public static <B extends SimpleEventHandlerInvoker.Builder<?>> SimpleEventHandlerInvoker.Builder<B> builder()

Instantiate a Builder to be able to create a SimpleEventHandlerInvoker.

The ListenerInvocationErrorHandler is defaulted to a LoggingErrorHandler and the SequencingPolicy to a SequentialPerAggregatePolicy. Providing at least one Event Handler is a hard requirement and as such should be provided.

Type Parameters:

B - An implementation of SimpleEventHandlerInvoker.Builder.

Returns:

A Builder to be able to create a SimpleEventHandlerInvoker.

eventHandlers

public List<EventMessageHandler> eventHandlers()

Gets the list of EventMessageHandler delegates in this invoker. These delegates are the end point of event handling.

Returns:

The list of EventMessageHandler delegates.

handle

public void handle(@Nonnull
                   EventMessage<?> message,
                   @Nonnull
                   Segment segment)
            throws Exception

Description copied from interface: EventHandlerInvoker

Handle the given message for the given segment.

Callers are recommended to invoke EventHandlerInvoker.canHandle(EventMessage, Segment) prior to invocation, but aren't required to do so. Implementations must ensure to take the given segment into account when processing messages.

Specified by:

handle in interface EventHandlerInvoker

Parameters:

message - The message to handle

segment - The segment for which to handle the message

Throws:

Exception - when an exception occurs while handling the message

sequencingPolicyMatchesSegment

protected boolean sequencingPolicyMatchesSegment(EventMessage<?> message,
                                                 Segment segment)

sequenceIdentifier

protected Object sequenceIdentifier(EventMessage<?> event)

invokeHandlers

protected void invokeHandlers(EventMessage<?> message)
                       throws Exception

Throws:

Exception

canHandle

public boolean canHandle(@Nonnull
                         EventMessage<?> eventMessage,
                         @Nonnull
                         Segment segment)

Description copied from interface: EventHandlerInvoker

Check whether or not this invoker has handlers that can handle the given eventMessage for a given segment.

Specified by:

canHandle in interface EventHandlerInvoker

Parameters:

eventMessage - The message to be processed

segment - The segment for which the event handler should be invoked

Returns:

true if the invoker has one or more handlers that can handle the given message, false otherwise

canHandleType

public boolean canHandleType(@Nonnull
                             Class<?> payloadType)

Description copied from interface: EventHandlerInvoker

Check whether or not this invoker has handlers that can handle the given payloadType.

Specified by:

canHandleType in interface EventHandlerInvoker

Parameters:

payloadType - The payloadType of the message to be processed

Returns:

true if the invoker has one or more handlers that can handle the given message, false otherwise

supportsReset

public boolean supportsReset()

Description copied from interface: EventHandlerInvoker

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

Specified by:

supportsReset in interface EventHandlerInvoker

Returns:

true if a reset is supported, otherwise false

performReset

public void performReset()

Description copied from interface: EventHandlerInvoker

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

Specified by:

performReset in interface EventHandlerInvoker

performReset

public <R> void performReset(@Nullable
                             R resetContext)

Description copied from interface: EventHandlerInvoker

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

Specified by:

performReset in interface EventHandlerInvoker

Type Parameters:

R - the type of the provided resetContext

Parameters:

resetContext - a R used to support the reset operation

getListenerInvocationErrorHandler

public ListenerInvocationErrorHandler getListenerInvocationErrorHandler()

Return the ListenerInvocationErrorHandler as configured for this EventHandlerInvoker.

Returns:

the ListenerInvocationErrorHandler as configured for this EventHandlerInvoker

getSequencingPolicy

public SequencingPolicy<? super EventMessage<?>> getSequencingPolicy()

Return the SequencingPolicy as configured for this EventHandlerInvoker.

Returns:

the SequencingPolicy as configured for this EventHandlerInvoker