/**
* Create a SagaMethodMessageHandler for the given <code>methodHandler</code>. The
* SagaMethodMessageHandler add information specific to the behavior of Sagas, such as the
* association value and creation policy.
*
* @param methodHandler The handler for incoming events
* @return a SagaMethodMessageHandler for the handler
*/
public static SagaMethodMessageHandler getInstance(MethodMessageHandler methodHandler) {
Method handlerMethod = methodHandler.getMethod();
SagaEventHandler handlerAnnotation = handlerMethod.getAnnotation(SagaEventHandler.class);
String associationPropertyName = handlerAnnotation.associationProperty();
Method associationProperty;
try {
associationProperty =
methodHandler.getPayloadType().getMethod(methodForProperty(associationPropertyName));
} catch (NoSuchMethodException e) {
throw new AxonConfigurationException(
format(
"SagaEventHandler %s.%s defines a property %s that is not "
+ "defined on the Event it declares to handle (%s)",
methodHandler.getMethod().getDeclaringClass().getName(),
methodHandler.getMethodName(),
associationPropertyName,
methodHandler.getPayloadType().getName()),
e);
}
String associationKey =
handlerAnnotation.keyName().isEmpty()
? associationPropertyName
: handlerAnnotation.keyName();
StartSaga startAnnotation = handlerMethod.getAnnotation(StartSaga.class);
SagaCreationPolicy sagaCreationPolicy;
if (startAnnotation == null) {
sagaCreationPolicy = SagaCreationPolicy.NONE;
} else if (startAnnotation.forceNew()) {
sagaCreationPolicy = SagaCreationPolicy.ALWAYS;
} else {
sagaCreationPolicy = SagaCreationPolicy.IF_NONE_FOUND;
}
return new SagaMethodMessageHandler(
sagaCreationPolicy, methodHandler, associationKey, associationProperty);
}
@PostConstruct
@SuppressWarnings({"unchecked"})
@Override
public synchronized void subscribe() {
for (final MethodMessageHandler commandHandler : inspector.getHandlers()) {
CommandHandler<Object> handler =
new CommandHandler<Object>() {
@Override
public Object handle(CommandMessage<Object> command, UnitOfWork unitOfWork)
throws Throwable {
T aggregate = loadAggregate(command);
try {
return commandHandler.invoke(aggregate, command);
} catch (InvocationTargetException e) {
throw e.getCause();
}
}
};
commandBus.subscribe(commandHandler.getPayloadType(), handler);
registeredCommandHandlers.put(commandHandler.getPayloadType(), handler);
}
for (final ConstructorCommandMessageHandler<T> handler : inspector.getConstructorHandlers()) {
commandBus.subscribe(
handler.getPayloadType(), new AnnotatedConstructorCommandHandler(handler));
}
}
@Override
public int compareTo(SagaMethodMessageHandler o) {
if (this.handlerMethod == null && o.handlerMethod == null) {
return 0;
} else if (this.handlerMethod == null) {
return -1;
} else if (o.handlerMethod == null) {
return 1;
}
return handlerMethod.compareTo(o.handlerMethod);
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
SagaMethodMessageHandler that = (SagaMethodMessageHandler) o;
return !(handlerMethod != null
? !handlerMethod.equals(that.handlerMethod)
: that.handlerMethod != null);
}
@Override
public int hashCode() {
return handlerMethod != null ? handlerMethod.hashCode() : 0;
}
/**
* Indicates whether this Handler is suitable for the given <code>message</code>.
*
* @param message The message to inspect
* @return <code>true</code> if this handler can handle the message, otherwise <code>false</code>.
*/
public boolean matches(EventMessage message) {
return handlerMethod != null && handlerMethod.matches(message);
}
/**
* Indicates whether the handler of the target event indicates an ending event handler (i.e. is
* annotated with {@link EndSaga}).
*
* @param event The event to investigate the handler for
* @return <code>true</code> if handling the given <code>event</code> should end the lifecycle of
* the Saga, <code>false</code> otherwise.
*/
public boolean isEndingEvent(EventMessage event) {
MethodMessageHandler handler = invoker.findHandlerMethod(event);
return handler != null && handler.getMethod().isAnnotationPresent(EndSaga.class);
}
