title: Sprint Integration DSL - Http Inbound adapter and poller
body: <p>I'm fairly new to Spring Integration and I'm trying to setup a simple use case:</p>
  
  <p>polling a remote REST endpoint, split the returned payload into multiple lines and send it to a Kafka outbound adapter. I successfully did something analogous, which uses a File Adapter, but I'm stuck with the HTTP adapter. I don't understand how to associate a poller to a HTTP inbound adapter.</p>
  
  <p>So far, my approach has been to create a simple flow:</p>
  
  <pre><code>return IntegrationFlows
    .from
      (
        Http.inboundChannelAdapter("http://localhost:8080/data")
          .requestMapping(m -&gt; m.methods(HttpMethod.GET))
          .replyTimeout(20)
        )
    .channel(INBOUND_DEMO_CHANNEL)
    .get();
  </code></pre>
  
  <p>The <code>inboundChannelAdapter</code> doesn't seem to accept a <code>Poller</code>. In my previous attempt using a File, I have created a <code>FileReadingMessageSource</code> so that my flow looked like:</p>
  
  <pre><code>return IntegrationFlows.from(fileReadingMessageSource,
      // POLLER CONFIGURATION
      .poller(Pollers.fixedDelay(period)
      ...
      .get();
  </code></pre>
  
  <p>but I can't find the equivalent of a HTTP message source.</p>