title: Integrate a Pollable channel in spring integation flow
body: <p>How to integrate a Pollable channel in the Integration flow. As my flow  is using a NullChannel instead of Pollable Channel.
      Can some one kindly provide  any pointer on this.</p>
  
  <pre><code>This is my Integration flow.
  
      @Bean
      public IntegrationFlow sftpInboundFlow() {
          System.out.println("enter sftpInboundFlow....."
                  + sftpSessionFactory.getSession());
          System.out.println("the channel is " + sftpInboundResultChannel);
          return IntegrationFlows
                  .from(Sftp.inboundAdapter(this.sftpSessionFactory)
                          .preserveTimestamp(true).remoteDirectory(remDir)
                          .regexFilter(".*\\.txt$")
                          .localFilenameExpression("#this.toUpperCase()")
                          .localDirectory(new File(localDir))
                          .remoteFileSeparator("/"),
                          new Consumer&lt;SourcePollingChannelAdapterSpec&gt;() {
                              @Override
                              public void accept(SourcePollingChannelAdapterSpec e) {
                                  e.id("sftpInboundAdapter")
                                          .autoStartup(true)
                                          .poller(Pollers.fixedRate(1000)
                                                  .maxMessagesPerPoll(1));
                              }
                          })
                  .channel(MessageChannels.queue("sftpInboundResultChannel"))
                  .get();
      }
  
  
  And I want to use this..
  
      @Autowired  
      private PollableChannel sftpInboundResultChannel; 
      in the .channel() method.
  </code></pre>
  
  <p>And the logs are...
  <code>
  [2015-07-22 18:48:05.497] - 2796 INFO [main] --- com.jcraft.jsch: SSH_MSG_NEWKEYS sent
  [2015-07-22 18:48:05.497] - 2796 INFO [main] --- com.jcraft.jsch: SSH_MSG_NEWKEYS received
  [2015-07-22 18:48:05.500] - 2796 INFO [main] --- com.jcraft.jsch: SSH_MSG_SERVICE_REQUEST sent
  [2015-07-22 18:48:05.501] - 2796 INFO [main] --- com.jcraft.jsch: SSH_MSG_SERVICE_ACCEPT received
  [2015-07-22 18:48:15.517] - 2796 INFO [main] --- com.jcraft.jsch: Authentications that can continue: gssapi-with-mic,publickey,keyboard-interactive,password
  [2015-07-22 18:48:15.517] - 2796 INFO [main] --- com.jcraft.jsch: Next authentication method: gssapi-with-mic
  [2015-07-22 18:48:15.522] - 2796 INFO [main] --- com.jcraft.jsch: Authentications that can continue: publickey,keyboard-interactive,password
  [2015-07-22 18:48:15.522] - 2796 INFO [main] --- com.jcraft.jsch: Next authentication method: publickey
  [2015-07-22 18:48:15.523] - 2796 INFO [main] --- com.jcraft.jsch: Authentications that can continue: password
  [2015-07-22 18:48:15.523] - 2796 INFO [main] --- com.jcraft.jsch: Next authentication method: password
  [2015-07-22 18:48:15.537] - 2796 INFO [main] --- com.jcraft.jsch: Authentication succeeded (password).
  enter sftpSessionFactory.....org.springframework.integration.sftp.session.SftpSession@1ffcd26
  enter sftpInboundFlow.....org.springframework.integration.sftp.session.SftpSession@13a462c
  the channel is org.springframework.integration.channel.NullChannel@d532ee
  [2015-07-22 18:48:15.827] - 2796 INFO [main] --- org.springframework.context.support.DefaultLifecycleProcessor: Starting beans in phase -2147483648
  [2015-07-22 18:48:15.828] - 2796 INFO [main] --- org.springframework.context.support.DefaultLifecycleProcessor: Starting beans in phase 0
  [2015-07-22 18:48:15.828] - 2796 INFO [main] --- org.springframework.integration.endpoint.EventDrivenConsumer: Adding {logging-channel-adapter:_org.springframework.integration.errorLogger} as a subscriber to the 'errorChannel' channel
  [2015-07-22 18:48:15.828] - 2796 INFO [main] --- org.springframework.integration.channel.PublishSubscribeChannel: Channel 'application.errorChannel' has 1 subscriber(s).
  [2015-07-22 18:48:15.829] - 2796 INFO [main] --- org.springframework.integration.endpoint.EventDrivenConsumer: started _org.springframework.integration.errorLogger
  [2015-07-22 18:48:15.829] - 2796 INFO [main] --- org.springframework.context.support.DefaultLifecycleProcessor: Starting beans in phase 1073741823
  [2015-07-22 18:48:15.832] - 2796 INFO [main] --- org.springframework.integration.endpoint.SourcePollingChannelAdapter: started sftpInboundAdapter
  [2015-07-22 18:48:15.834] - 2796 INFO [main] --- src.MainSftpInBoundDsl: Started MainSftpInBoundDsl in 11.019 seconds (JVM running for 11.182)
  enter main.....
  enter main.....
  [2015-07-22 18:48:16.040] - 2796 INFO [task-scheduler-1] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\AMARJEET.TXT, headers={timestamp=1437571096040, id=ddc20f6d-26ee-7eef-f59e-b5207dcdc8c7}]]
  [2015-07-22 18:48:16.832] - 2796 INFO [task-scheduler-1] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\INFO.TXT, headers={timestamp=1437571096832, id=361b55d5-884e-9001-d513-ddc81926bf85}]]
  [2015-07-22 18:48:17.832] - 2796 INFO [task-scheduler-2] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\KKKK.TXT, headers={timestamp=1437571097832, id=49deb17c-50e3-4315-dfa2-cc443a35bd1c}]]
  [2015-07-22 18:48:18.832] - 2796 INFO [task-scheduler-1] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\LA.TXT, headers={timestamp=1437571098832, id=88def298-ab86-1d63-039e-c81c70ae6819}]]
  [2015-07-22 18:48:19.832] - 2796 INFO [task-scheduler-3] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\POC.TXT, headers={timestamp=1437571099832, id=d78b36eb-10f5-ce83-ba4c-cd24a806480b}]]
  [2015-07-22 18:48:20.832] - 2796 INFO [task-scheduler-2] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\PPPP.TXT, headers={timestamp=1437571100832, id=4e727ebb-b4de-be19-6a92-afb3be24576f}]]
  [2015-07-22 18:48:21.832] - 2796 INFO [task-scheduler-4] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\REFERENCE.TXT, headers={timestamp=1437571101832, id=3d611371-431c-6b1e-0e17-377f5607de96}]]
  [2015-07-22 18:48:22.831] - 2796 INFO [task-scheduler-1] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\RRRRR.TXT, headers={timestamp=1437571102831, id=707e566c-ccfa-6c32-16d6-1f27ec73abaf}]]
  [2015-07-22 18:48:23.832] - 2796 INFO [task-scheduler-5] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\SFTP.TXT, headers={timestamp=1437571103832, id=b3c979ff-fcd2-e1ff-8b37-6b8f2803637a}]]
  [2015-07-22 18:48:24.832] - 2796 INFO [task-scheduler-3] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\TEST.TXT, headers={timestamp=1437571104832, id=98d43e62-8e5f-69bc-7617-4706761eaf86}]]
  [2015-07-22 18:48:25.832] - 2796 INFO [task-scheduler-3] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\XSS.TXT, headers={timestamp=1437571105832, id=77b28259-0287-0ef5-825f-5345d6c21c21}]]
  [2015-07-22 18:48:26.832] - 2796 INFO [task-scheduler-3] --- org.springframework.integration.file.FileReadingMessageSource: Created message: [GenericMessage [payload=D:\local_copy\ZZZZ.TXT, headers={timestamp=1437571106832, id=b5644a62-8c8c-86d2-e016-75fff01c70b4}]]
  </code></p>