Package io.fluxcapacitor.javaclient.publishing

Interface RequestHandler

All Superinterfaces:

AutoCloseable

All Known Implementing Classes:

DefaultRequestHandler

public interface RequestHandler
extends AutoCloseable

Handles the lifecycle of request/response interactions in a Flux Capacitor client.

A RequestHandler is responsible for sending requests—such as commands, queries, or web requests— and asynchronously completing them when a corresponding response is received. Requests may be handled locally or remotely via the Flux platform.

Handling Strategies

• Local Handling: If a request matches a locally registered handler, the RequestHandler may invoke it directly. The result is either returned immediately or asynchronously via a CompletableFuture.
• Remote Handling: If the request is dispatched to the Flux platform, the handler listens for the corresponding response via a TrackingClient subscribed to the appropriate result log (e.g. result or web response log). Responses are correlated using a unique requestId embedded in each SerializedMessage.

To prevent unnecessary message traffic, the underlying tracker is typically configured with:

• filterMessageTarget = true, so only messages targeted to this client are delivered.
• clientControlledIndex = true, allowing precise control over result consumption.

A RequestHandler implementation must ensure lifecycle management, including resource cleanup and deregistration when close() is invoked.

Method Summary

Modifier and Type	Method	Description
void	close()	Releases all resources associated with this handler.
default CompletableFuture<SerializedMessage>	sendRequest(SerializedMessage request, Consumer<SerializedMessage> requestSender)	Sends a single request and returns a future that completes when the corresponding response is received.
CompletableFuture<SerializedMessage>	sendRequest(SerializedMessage request, Consumer<SerializedMessage> requestSender, Duration timeout)	Sends a single request with a custom timeout and returns a future for the corresponding response.
CompletableFuture<SerializedMessage>	sendRequest(SerializedMessage request, Consumer<SerializedMessage> requestSender, Duration timeout, Consumer<SerializedMessage> intermediateCallback)
default CompletableFuture<SerializedMessage>	sendRequest(SerializedMessage request, Consumer<SerializedMessage> requestSender, Consumer<SerializedMessage> intermediateCallback)
List<CompletableFuture<SerializedMessage>>	sendRequests(List<SerializedMessage> requests, Consumer<List<SerializedMessage>> requestSender)	Sends multiple requests and returns a list of futures for their corresponding responses.
List<CompletableFuture<SerializedMessage>>	sendRequests(List<SerializedMessage> requests, Consumer<List<SerializedMessage>> requestSender, Duration timeout)	Sends multiple requests with a custom timeout and returns a list of futures for their responses.

Method Details

sendRequest

default CompletableFuture<SerializedMessage> sendRequest(SerializedMessage request,
 Consumer<SerializedMessage> requestSender)

Sends a single request and returns a future that completes when the corresponding response is received.

The request is assigned a unique requestId and dispatched using the provided sender. The returned CompletableFuture is completed with the result or failed on timeout.

Parameters:

request - The request message to be sent.

requestSender - A callback used to dispatch the request (e.g. to a gateway or transport layer).

Returns:

A CompletableFuture that completes with the response message or fails on timeout.

sendRequest

CompletableFuture<SerializedMessage> sendRequest(SerializedMessage request,
 Consumer<SerializedMessage> requestSender,
 @Nullable
 Duration timeout)

Sends a single request with a custom timeout and returns a future for the corresponding response.

Parameters:

request - The request message to be sent.

requestSender - A callback used to dispatch the request.

timeout - The timeout for this request. A negative value indicates no timeout.

Returns:

A CompletableFuture that completes with the response or fails on timeout.

sendRequests

List<CompletableFuture<SerializedMessage>> sendRequests(List<SerializedMessage> requests,
 Consumer<List<SerializedMessage>> requestSender)

Sends multiple requests and returns a list of futures for their corresponding responses.

Each request is assigned a unique requestId and dispatched using the given sender. The returned list preserves the order of the input requests.

Parameters:

requests - The requests to send.

requestSender - A callback used to dispatch the requests (e.g. batch publisher).

Returns:

A list of CompletableFuture instances, one for each request.

sendRequests

List<CompletableFuture<SerializedMessage>> sendRequests(List<SerializedMessage> requests,
 Consumer<List<SerializedMessage>> requestSender,
 @Nullable
 Duration timeout)

Sends multiple requests with a custom timeout and returns a list of futures for their responses.

Parameters:

requests - The requests to send.

requestSender - A callback used to dispatch the requests.

timeout - The timeout to apply per request. A negative value disables the timeout.

Returns:

A list of CompletableFuture instances, one for each request.

sendRequest

default CompletableFuture<SerializedMessage> sendRequest(SerializedMessage request,
 Consumer<SerializedMessage> requestSender,
 Consumer<SerializedMessage> intermediateCallback)

sendRequest

CompletableFuture<SerializedMessage> sendRequest(SerializedMessage request,
 Consumer<SerializedMessage> requestSender,
 Duration timeout,
 Consumer<SerializedMessage> intermediateCallback)

close

void close()

Releases all resources associated with this handler.

This typically shuts down any underlying TrackingClient subscriptions, and may cancel or complete any outstanding requests.

Specified by:

close in interface AutoCloseable