org.axonframework.eventhandling

Class SimpleEventHandlerInvoker

java.lang.Object

org.axonframework.eventhandling.SimpleEventHandlerInvoker

All Implemented Interfaces:

EventHandlerInvoker

public class SimpleEventHandlerInvoker
extends Object
implements EventHandlerInvoker

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

Author:

Rene de Waele

Constructor Summary

Constructors

Constructor and Description
SimpleEventHandlerInvoker(List<?> eventListeners, ListenerInvocationErrorHandler listenerInvocationErrorHandler) Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners.
SimpleEventHandlerInvoker(List<?> eventListeners, ListenerInvocationErrorHandler listenerInvocationErrorHandler, SequencingPolicy<? super EventMessage<?>> sequencingPolicy) Initialize the EventHandlerInvoker to invoke the given eventListeners, using the given listenerInvocationErrorHandler when an error occurs invoking these handlers and the given sequencingPolicy to describe the expected sequencing of event messages
SimpleEventHandlerInvoker(List<?> eventListeners, ParameterResolverFactory parameterResolverFactory, ListenerInvocationErrorHandler listenerInvocationErrorHandler) Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners.
SimpleEventHandlerInvoker(List<?> eventListeners, ParameterResolverFactory parameterResolverFactory, ListenerInvocationErrorHandler listenerInvocationErrorHandler, SequencingPolicy<? super EventMessage<?>> sequencingPolicy) Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners.
SimpleEventHandlerInvoker(Object... eventListeners) Initializes a SimpleEventHandlerInvoker containing one or more eventListeners.

Method Summary

Modifier and Type	Method and Description
boolean	canHandle(EventMessage<?> eventMessage, Segment segment) Check whether or not this invoker has handlers that can handle the given eventMessage for a given segment.
List<?>	eventListeners() Gets the list of event listener delegates.
ListenerInvocationErrorHandler	getListenerInvocationErrorHandler()
SequencingPolicy<? super EventMessage<?>>	getSequencingPolicy()
void	handle(EventMessage<?> message, Segment segment) Handle the given message for the given segment.
void	performReset() Performs any activities that are required to reset the state managed by handlers assigned to this invoker.
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

Methods inherited from interface org.axonframework.eventhandling.EventHandlerInvoker

handle

Constructor Detail

SimpleEventHandlerInvoker

public SimpleEventHandlerInvoker(Object... eventListeners)

Initializes a SimpleEventHandlerInvoker containing one or more eventListeners. If an event listener is assignable to EventListener it will registered as is. If not, it will be wrapped by a new AnnotationEventListenerAdapter.

Events handled by the invoker will be passed to all the given eventListeners. If an exception is triggered during event handling it will be logged using a LoggingErrorHandler but otherwise ignored.

When this invoker is invoked for multiple Segments (i.e. using parallel processing), events from the same Aggregate are guaranteed to be processed in sequence (see SequentialPerAggregatePolicy).

Parameters:

eventListeners - one or more event listeners to register with this invoker

SimpleEventHandlerInvoker

public SimpleEventHandlerInvoker(List<?> eventListeners,
                                 ListenerInvocationErrorHandler listenerInvocationErrorHandler)

Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners. If an event listener is assignable to EventListener it will registered as is. If not, it will be wrapped by a new AnnotationEventListenerAdapter.

Events handled by the invoker will be passed to all the given eventListeners. If an exception is triggered during event handling it will be handled by the given listenerErrorHandler.

When this invoker is invoked for multiple Segments (i.e. using parallel processing), events from the same Aggregate are guaranteed to be processed in sequence (see SequentialPerAggregatePolicy).

Parameters:

eventListeners - list of event listeners to register with this invoker

listenerInvocationErrorHandler - error handler that handles exceptions during processing

SimpleEventHandlerInvoker

public SimpleEventHandlerInvoker(List<?> eventListeners,
                                 ListenerInvocationErrorHandler listenerInvocationErrorHandler,
                                 SequencingPolicy<? super EventMessage<?>> sequencingPolicy)

Initialize the EventHandlerInvoker to invoke the given eventListeners, using the given listenerInvocationErrorHandler when an error occurs invoking these handlers and the given sequencingPolicy to describe the expected sequencing of event messages

Parameters:

eventListeners - The listeners to invoke

listenerInvocationErrorHandler - The error handler to invoke when an error occurs

sequencingPolicy - The policy describing the expectations of sequential processing

SimpleEventHandlerInvoker

public SimpleEventHandlerInvoker(List<?> eventListeners,
                                 ParameterResolverFactory parameterResolverFactory,
                                 ListenerInvocationErrorHandler listenerInvocationErrorHandler)

Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners. If an event listener is assignable to EventListener it will registered as is. If not, it will be wrapped by a new AnnotationEventListenerAdapter.

Events handled by the invoker will be passed to all the given eventListeners. If an exception is triggered during event handling it will be handled by the given listenerErrorHandler.

Parameters:

eventListeners - list of event listeners to register with this invoker

parameterResolverFactory - The parameter resolver factory to resolve parameters of the Event Handler methods with

listenerInvocationErrorHandler - error handler that handles exceptions during processing

SimpleEventHandlerInvoker

public SimpleEventHandlerInvoker(List<?> eventListeners,
                                 ParameterResolverFactory parameterResolverFactory,
                                 ListenerInvocationErrorHandler listenerInvocationErrorHandler,
                                 SequencingPolicy<? super EventMessage<?>> sequencingPolicy)

Initializes a SimpleEventHandlerInvoker containing the given list of eventListeners. If an event listener is assignable to EventListener it will registered as is. If not, it will be wrapped by a new AnnotationEventListenerAdapter.

Events handled by the invoker will be passed to all the given eventListeners. If an exception is triggered during event handling it will be handled by the given listenerErrorHandler.

Parameters:

eventListeners - list of event listeners to register with this invoker

parameterResolverFactory - The parameter resolver factory to resolve parameters of the Event Handler methods with

listenerInvocationErrorHandler - error handler that handles exceptions during processing

sequencingPolicy - The policy describing the expectations of sequential processing

Method Detail

eventListeners

public List<?> eventListeners()

Gets the list of event listener delegates. This delegates are the end point of event handling.

Returns:

the list of event listener delegates

handle

public void handle(EventMessage<?> message,
                   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

canHandle

public boolean canHandle(EventMessage<?> eventMessage,
                         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

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

getListenerInvocationErrorHandler

public ListenerInvocationErrorHandler getListenerInvocationErrorHandler()

getSequencingPolicy

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