org.axonframework.eventhandling

Class SimpleEventHandlerInvoker.Builder<B extends SimpleEventHandlerInvoker.Builder<?>>

java.lang.Object

org.axonframework.eventhandling.SimpleEventHandlerInvoker.Builder<B>

Direct Known Subclasses:

DeadLetteringEventHandlerInvoker.Builder

Enclosing class:

SimpleEventHandlerInvoker

public static class SimpleEventHandlerInvoker.Builder<B extends SimpleEventHandlerInvoker.Builder<?>>
extends Object

Builder class to instantiate 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.

Constructor Summary

Constructors

Constructor and Description
Builder()

Method Summary

Modifier and Type	Method and Description
SimpleEventHandlerInvoker	build() Initializes a SimpleEventHandlerInvoker as specified through this Builder.
B	eventHandlers(List<?> eventHandlers) Sets the eventHandlers this EventHandlerInvoker will forward all its events to.
B	eventHandlers(Object... eventHandlers) Sets the eventHandlers this EventHandlerInvoker will forward all its events to.
B	handlerDefinition(HandlerDefinition handlerDefinition) Sets the HandlerDefinition used to create concrete handlers in the annotated handlers in the AnnotationEventHandlerAdapter this EventHandlerInvoker instantiates.
B	listenerInvocationErrorHandler(ListenerInvocationErrorHandler listenerInvocationErrorHandler) Sets the ListenerInvocationErrorHandler dealing with exceptions thrown by the configured event handlers.
B	parameterResolverFactory(ParameterResolverFactory parameterResolverFactory) Sets the ParameterResolverFactory used to resolve parameter values for annotated handlers in the AnnotationEventHandlerAdapter this EventHandlerInvoker instantiates.
B	sequencingPolicy(SequencingPolicy<? super EventMessage<?>> sequencingPolicy) Sets the SequencingPolicy in charge of deciding whether a given event should be handled (through EventHandlerInvoker.handle(EventMessage, Segment)) by the given Segment.
protected void	validate() Validates whether the fields contained in this Builder are set accordingly.
AnnotationEventHandlerAdapter	wrapEventMessageHandler(Object eventHandler) Wrap a given eventHandler in an AnnotationEventHandlerAdapter to allow this EventHandlerInvoker to correctly pass EventMessages to it.

Methods inherited from class java.lang.Object

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

Constructor Detail

Builder

public Builder()

Method Detail

eventHandlers

public B eventHandlers(Object... eventHandlers)

Sets the eventHandlers this EventHandlerInvoker will forward all its events to. If an event handler is assignable to EventMessageHandler it will register as is. If not, it will be wrapped by a new AnnotationEventHandlerAdapter.

Parameters:

eventHandlers - an array of Objects which can handle events

Returns:

the current Builder instance, for fluent interfacing

eventHandlers

public B eventHandlers(@Nonnull
                       List<?> eventHandlers)

Sets the eventHandlers this EventHandlerInvoker will forward all its events to. If an event handler is assignable to EventMessageHandler it will register as is. If not, it will be wrapped by a new AnnotationEventHandlerAdapter.

Parameters:

eventHandlers - a List of Objects which can handle events

Returns:

the current Builder instance, for fluent interfacing

parameterResolverFactory

public B parameterResolverFactory(@Nonnull
                                  ParameterResolverFactory parameterResolverFactory)

Sets the ParameterResolverFactory used to resolve parameter values for annotated handlers in the AnnotationEventHandlerAdapter this EventHandlerInvoker instantiates. This invoker will only instantiate a new EventMessageHandler if a given Event Handler (through eventHandlers(Object...) or eventHandlers(List)) is not assignable to EventMessageHandler.

Parameters:

parameterResolverFactory - the ParameterResolverFactory used to resolve parameter values for instantiated AnnotationEventHandlerAdapters

Returns:

the current Builder instance, for fluent interfacing

handlerDefinition

public B handlerDefinition(@Nonnull
                           HandlerDefinition handlerDefinition)

Sets the HandlerDefinition used to create concrete handlers in the annotated handlers in the AnnotationEventHandlerAdapter this EventHandlerInvoker instantiates. This invoker will only instantiate a new EventMessageHandler if a given Event Handler (through eventHandlers(Object...) or eventHandlers(List)) is not assignable to EventMessageHandler.

Parameters:

handlerDefinition - the HandlerDefinition used to create concrete handlers in the instantiated AnnotationEventHandlerAdapters

Returns:

the current Builder instance, for fluent interfacing

listenerInvocationErrorHandler

public B listenerInvocationErrorHandler(@Nonnull
                                        ListenerInvocationErrorHandler listenerInvocationErrorHandler)

Sets the ListenerInvocationErrorHandler dealing with exceptions thrown by the configured event handlers. Defaults to a LoggingErrorHandler.

Parameters:

listenerInvocationErrorHandler - The error handler dealing with exceptions thrown by the configured event handlers

Returns:

the current Builder instance, for fluent interfacing

sequencingPolicy

public B sequencingPolicy(@Nonnull
                          SequencingPolicy<? super EventMessage<?>> sequencingPolicy)

Sets the SequencingPolicy in charge of deciding whether a given event should be handled (through EventHandlerInvoker.handle(EventMessage, Segment)) by the given Segment. Used when this EventHandlerInvoker is invoked for multiple Segments (i.e. using parallel processing). Defaults to a SequentialPerAggregatePolicy,

Parameters:

sequencingPolicy - a SequencingPolicy in charge of deciding whether a given event should be handled by the given Segment

Returns:

the current Builder instance, for fluent interfacing

build

public SimpleEventHandlerInvoker build()

Initializes a SimpleEventHandlerInvoker as specified through this Builder.

Returns:

a SimpleEventHandlerInvoker as specified through this Builder

wrapEventMessageHandler

public AnnotationEventHandlerAdapter wrapEventMessageHandler(@Nonnull
                                                             Object eventHandler)

Wrap a given eventHandler in an AnnotationEventHandlerAdapter to allow this EventHandlerInvoker to correctly pass EventMessages to it. If a ParameterResolverFactory or both a ParameterResolverFactory and HandlerDefinition are present, one/both will be given to the AnnotationEventHandlerAdapter

Parameters:

eventHandler - an Object which will be wrapped in an AnnotationEventHandlerAdapter

Returns:

an AnnotationEventHandlerAdapter which the given eventHandler will be wrapped in

validate

protected void validate()
                 throws AxonConfigurationException

Validates whether the fields contained in this Builder are set accordingly.

Throws:

AxonConfigurationException - if one field is asserted to be incorrect according to the Builder's specifications