Spring Integration DSL: Simple way to send some messages to a Flow inputChannel

Question

If I want to generate some sample data for testing purposes of the Spring Integration DSL functionality, one way I have come up with so far is like this:

@Bean
public IntegrationFlow myFlow() {
    return IntegrationFlows
            .from(Http.inboundChannelAdapter("numbers").get())
            .scatterGather(s -> s
                    .applySequence(true)
                    .recipientFlow(f -> f.handle((a, b) -> Arrays.asList(1,2,3,4,5,6,7,8,9,10)))
            )
            .split() // unpack the wrapped list
            .split() // unpack the elements of the list
            .log()
            .get();
}

Is there another/better way to do the same thing ? Using the Scatter-Gather EIP seems like overkill for something so basic...

Answer 1

I found a simpler way of doing the same thing using .transform() instead of .scatterGather()

@Bean
public IntegrationFlow testFlow() {
    return IntegrationFlows
            .from(Http.inboundChannelAdapter("test").get())
            .transform(t -> Arrays.asList(1,2,3,4,5,6,7,8,9,10))
            .split() // unpack the wrapped list
            .split() // unpack the elements of the list
            .get();
}

And here's another way you could do it using .gateway()

@Bean
public IntegrationFlow testFlow() {
    return IntegrationFlows
            .from(Http.inboundChannelAdapter("test").get())
            .gateway(f -> f.handle((a, b) -> Arrays.asList(1,2,3,4,5,6,7,8,9,10)))
            .split() // unpack the elements of the list
            .get();
}

And yet another:

@Bean
IntegrationFlow fromSupplier() {
    return IntegrationFlow.fromSupplier(() -> List.of(1,2,3,4), 
                    s -> s.poller(p -> p.fixedDelay(1, TimeUnit.DAYS)))
            .log(Message::getPayload)
            .nullChannel();
}