Class DefaultEntityHelper

java.lang.Object

io.fluxzero.sdk.modeling.DefaultEntityHelper

All Implemented Interfaces:

EntityHelper

public class DefaultEntityHelper
extends Object
implements EntityHelper

The DefaultEntityHelper provides the default implementation of the EntityHelper interface.

It is responsible for orchestrating the behavior of domain model entities with respect to: - Intercepting messages using @InterceptApply handlers - Applying updates or events via @Apply handlers - Validating updates and asserting legal state transitions using @AssertLegal handlers

This helper is heavily used during message handling and event sourcing to delegate message processing and validation logic to methods annotated on the entity class or its nested members.

The class supports efficient handler resolution through memoized lookups, enabling fast, repeatable application of complex domain behaviors.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
protected static class	DefaultEntityHelper.DeserializingMessageWithEntity	Decorates a DeserializingMessage with an associated entity.
protected static class	DefaultEntityHelper.MessageWithEntity	Wraps a message and its corresponding entity for use in interception or handler invocation.

Constructor Summary

Constructors

Constructor	Description
DefaultEntityHelper(List<ParameterResolver<? super DeserializingMessage>> parameterResolvers, boolean disablePayloadValidation)	Creates a new helper using the given parameter resolvers and configuration.

Method Summary

Modifier and Type	Method	Description
Optional<HandlerInvoker>	applyInvoker(DeserializingMessage event, Entity<?> entity, boolean searchChildren)	Finds a handler method annotated with @Apply and wraps it to preserve apply context flags.
<E extends Exception> void	assertLegal(Object value, Entity<?> entity)	Performs a validation check using @AssertLegal handlers for the provided payload.
<E extends Exception> Optional<E>	checkLegality(Object value, Entity<?> entity)	Returns an exception if the value is illegal for the current entity, or Optional.empty() if legal.
protected Optional<HandlerInvoker>	getInterceptInvoker(DefaultEntityHelper.MessageWithEntity m)	Recursively resolves the best-matching interceptor method, including nested members.
static Aggregate	getRootAnnotation(Class<?> type)	Returns the cached or default @Aggregate annotation for a given type.
Stream<?>	intercept(Object value, Entity<?> entity)	Intercepts the given value using @InterceptApply methods defined on the entity.
boolean	isLegal(Object value, Entity<?> entity)	Convenience method that returns true if checkLegality(Object, Entity) yields no error.

Methods inherited from class Object

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

Methods inherited from interface EntityHelper

applyInvoker

Constructor Details

DefaultEntityHelper

public DefaultEntityHelper(List<ParameterResolver<? super DeserializingMessage>> parameterResolvers,
 boolean disablePayloadValidation)

Creates a new helper using the given parameter resolvers and configuration.

Parameters:

parameterResolvers - Resolvers used to inject values into annotated handler methods

disablePayloadValidation - If true, disables bean validation of payloads

Method Details

getRootAnnotation

public static Aggregate getRootAnnotation(Class<?> type)

Returns the cached or default @Aggregate annotation for a given type.

intercept

public Stream<?> intercept(Object value,
 Entity<?> entity)

Intercepts the given value using @InterceptApply methods defined on the entity. Interceptors may transform or replace the original message.

Specified by:

intercept in interface EntityHelper

Parameters:

value - the value to be intercepted, typically the payload of a message

entity - the entity receiving the value

Returns:

a stream of intercepted values or messages to be applied

getInterceptInvoker

protected Optional<HandlerInvoker> getInterceptInvoker(DefaultEntityHelper.MessageWithEntity m)

Recursively resolves the best-matching interceptor method, including nested members.

applyInvoker

public Optional<HandlerInvoker> applyInvoker(DeserializingMessage event,
 Entity<?> entity,
 boolean searchChildren)

Finds a handler method annotated with @Apply and wraps it to preserve apply context flags.

Specified by:

applyInvoker in interface EntityHelper

Parameters:

event - the event to apply

entity - the root or intermediate entity

searchChildren - whether to search nested child entities for applicable handlers

Returns:

a handler invoker if a suitable method is located

assertLegal

public <E extends Exception> void assertLegal(Object value,
 Entity<?> entity)
                                       throws E

Performs a validation check using @AssertLegal handlers for the provided payload. This method is called both before and after the handler completes, depending on the annotation's settings.

Specified by:

assertLegal in interface EntityHelper

Type Parameters:

E - the type of exception that may be thrown

Parameters:

value - the value to validate

entity - the current entity state

Throws:

E - if the value is deemed illegal

checkLegality

public <E extends Exception> Optional<E> checkLegality(Object value,
 Entity<?> entity)

Returns an exception if the value is illegal for the current entity, or Optional.empty() if legal.

Specified by:

checkLegality in interface EntityHelper

Type Parameters:

E - the type of exception

Parameters:

value - the value to validate

entity - the entity context

Returns:

an exception if illegal, or an empty Optional if legal

isLegal

public boolean isLegal(Object value,
 Entity<?> entity)

Convenience method that returns true if checkLegality(Object, Entity) yields no error.

Specified by:

isLegal in interface EntityHelper

Parameters:

value - the value to check

entity - the entity context

Returns:

true if legal, false otherwise