Interface DispatchInterceptor

All Known Implementing Classes:

AdhocDispatchInterceptor, AuthenticatingInterceptor, CorrelatingInterceptor, DataProtectionInterceptor, MessageRoutingInterceptor, SchedulingInterceptor, WebResponseCompressingInterceptor, WebsocketResponseInterceptor

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface DispatchInterceptor

Mechanism that enables modification, monitoring, or conditional suppression of messages before they are dispatched to local handlers or published to the Fluxzero Runtime.

A DispatchInterceptor allows observing and transforming messages during the dispatch process. It is typically used to inject metadata, rewrite payloads, log outgoing messages, or prevent dispatching certain messages based on custom rules.

Key behaviors:

• interceptDispatch(Message, MessageType, String) is used for altering or blocking a message before it's handled or published.
• modifySerializedMessage(SerializedMessage, Message, MessageType, String) can change the final serialized message before it's stored or sent to the Fluxzero Runtime.
• monitorDispatch(Message, MessageType, String, String) is a post-processing hook for monitoring without side effects or blocking.

See Also:

• FluxzeroBuilder.addDispatchInterceptor(DispatchInterceptor, MessageType...)

Field Summary

Fields

Modifier and Type	Field	Description
static final DispatchInterceptor	noOp	No-op implementation of the DispatchInterceptor that returns the original message unchanged.

Method Summary

Modifier and Type	Method	Description
default DispatchInterceptor	andThen(DispatchInterceptor nextInterceptor)	Chains this interceptor with another.
Message	interceptDispatch(Message message, MessageType messageType, String topic)	Intercepts the dispatch of a message before it is serialized and published or locally handled.
default SerializedMessage	modifySerializedMessage(SerializedMessage serializedMessage, Message message, MessageType messageType, String topic)	Allows modifications to the serialized representation of the message before it is actually published.
default void	monitorDispatch(Message message, MessageType messageType, String topic, String namespace)	Hook to observe the dispatch of a message.

Field Details

noOp

static final DispatchInterceptor noOp

No-op implementation of the DispatchInterceptor that returns the original message unchanged.

Method Details

interceptDispatch

Message interceptDispatch(Message message,
 MessageType messageType,
 String topic)

Intercepts the dispatch of a message before it is serialized and published or locally handled.

You may modify the message or return null to block dispatching. Throwing an exception also prevents dispatching.

Parameters:

message - the message to be dispatched

messageType - the type of the message (e.g., COMMAND, EVENT, etc.)

topic - the target topic or null if not applicable

Returns:

the modified message, the same message, or null to prevent dispatch

modifySerializedMessage

default SerializedMessage modifySerializedMessage(SerializedMessage serializedMessage,
 Message message,
 MessageType messageType,
 String topic)

Allows modifications to the serialized representation of the message before it is actually published.

This is called after interceptDispatch(Message, MessageType, String) and should not be used to block dispatching — use interceptDispatch(Message, MessageType, String) for that purpose instead.

Parameters:

serializedMessage - the serialized form of the message

message - the deserialized message object

messageType - the message type

topic - the target topic

Returns:

the modified or original SerializedMessage

monitorDispatch

default void monitorDispatch(Message message,
 MessageType messageType,
 String topic,
 String namespace)

Hook to observe the dispatch of a message. This method is called after all interceptors have had a chance to block or modify the message.

Use this for logging or metrics, but not to alter or block the message.

Parameters:

message - the final message about to be handled or published

messageType - the type of the message

topic - the topic to which the message is dispatched (can be null)

namespace - the namespace to which the message is dispatched (can be null)

andThen

default DispatchInterceptor andThen(DispatchInterceptor nextInterceptor)

Chains this interceptor with another. The resulting interceptor applies this one first, then the next one.

Parameters:

nextInterceptor - the interceptor to run after this one

Returns:

a new DispatchInterceptor representing the combined logic