How to poll for multiple files at once with Spring Integration with WebFlux? - spring-integration

Question

I have the following configuration below for file monitoring using Spring Integration and WebFlux.
It works well, but if I drop in 100 files it will pick up one file at a time with a 10 second gap between the "Received a notification of new file" log messages.
How do I poll for multiple files at once, so I don't have to wait 1000 seconds for all my files to finally register?
#Configuration
#EnableIntegration
public class FileMonitoringConfig {
private static final Logger logger =
LoggerFactory.getLogger(FileMonitoringConfig.class.getName());
#Value("${monitoring.folder}")
private String monitoringFolder;
#Value("${monitoring.polling-in-seconds:10}")
private int pollingInSeconds;
#Bean
Publisher<Message<Object>> myMessagePublisher() {
return IntegrationFlows.from(
Files.inboundAdapter(new File(monitoringFolder))
.useWatchService(false),
e -> e.poller(Pollers.fixedDelay(pollingInSeconds, TimeUnit.SECONDS)))
.channel(myChannel())
.toReactivePublisher();
}
#Bean
Function<Flux<Message<Object>>, Publisher<Message<Object>>> myReactiveSource() {
return flux -> myMessagePublisher();
}
#Bean
FluxMessageChannel myChannel() {
return new FluxMessageChannel();
}
#Bean
#ServiceActivator(
inputChannel = "myChannel",
async = "true",
reactive = #Reactive("myReactiveSource"))
ReactiveMessageHandler myMessageHandler() {
return new ReactiveMessageHandler() {
#Override
public Mono<Void> handleMessage(Message<?> message) throws MessagingException {
return Mono.fromFuture(doHandle(message));
}
private CompletableFuture<Void> doHandle(Message<?> message) {
return CompletableFuture.runAsync(
() -> {
logger.info("Received a notification of new file: {}", message.getPayload());
File file = (File) message.getPayload();
});
}
};
}
}

Answer 1

The Inbound Channel Adapter polls a single data record from the source per poll cycle.
Consider to add maxMessagesPerPoll(-1) to your poller() configuration.
See more in docs: https://docs.spring.io/spring-integration/docs/current/reference/html/core.html#channel-adapter-namespace-inbound